diff --git a/libs/standard-tests/langchain_tests/base.py b/libs/standard-tests/langchain_tests/base.py
index c54b84055a7..0f9156673c1 100644
--- a/libs/standard-tests/langchain_tests/base.py
+++ b/libs/standard-tests/langchain_tests/base.py
@@ -1,8 +1,13 @@
+"""Standard tests."""
+
 from abc import ABC
 
 
 class BaseStandardTests(ABC):
-    """:private:"""
+    """Base class for standard tests.
+
+    :private:
+    """
 
     def test_no_overrides_DO_NOT_OVERRIDE(self) -> None:
         """Test that no standard tests are overridden.
diff --git a/libs/standard-tests/langchain_tests/conftest.py b/libs/standard-tests/langchain_tests/conftest.py
index f8536c39a79..b1674bc963d 100644
--- a/libs/standard-tests/langchain_tests/conftest.py
+++ b/libs/standard-tests/langchain_tests/conftest.py
@@ -1,3 +1,5 @@
+"""Pytest conftest."""
+
 import gzip
 from os import PathLike
 from pathlib import Path
@@ -88,7 +90,7 @@ _BASE_FILTER_HEADERS = [
 
 @pytest.fixture(scope="session")
 def _base_vcr_config() -> dict:
-    """Get configuration that every cassette will receive.
+    """Return VCR configuration that every cassette will receive.
 
     (Anything permitted by ``vcr.VCR(**kwargs)`` can be put here.)
     """
@@ -105,4 +107,5 @@ def _base_vcr_config() -> dict:
 
 @pytest.fixture(scope="session")
 def vcr_config(_base_vcr_config: dict) -> dict:
+    """VCR config fixture."""
     return _base_vcr_config
diff --git a/libs/standard-tests/langchain_tests/integration_tests/__init__.py b/libs/standard-tests/langchain_tests/integration_tests/__init__.py
index fbe4888d1e5..2a311bb8c9d 100644
--- a/libs/standard-tests/langchain_tests/integration_tests/__init__.py
+++ b/libs/standard-tests/langchain_tests/integration_tests/__init__.py
@@ -1,3 +1,5 @@
+"""Integration tests for LangChain components."""
+
 # ruff: noqa: E402
 import pytest
 
diff --git a/libs/standard-tests/langchain_tests/integration_tests/base_store.py b/libs/standard-tests/langchain_tests/integration_tests/base_store.py
index 31daa8c2307..cba4c245e1d 100644
--- a/libs/standard-tests/langchain_tests/integration_tests/base_store.py
+++ b/libs/standard-tests/langchain_tests/integration_tests/base_store.py
@@ -62,7 +62,9 @@ class BaseStoreSyncTests(BaseStandardTests, Generic[V]):
         assert kv_store.mget(["foo", "bar"]) == [foo, bar]
 
     def test_store_still_empty(self, kv_store: BaseStore[str, V]) -> None:
-        """This test should follow a test that sets values.
+        """Test that the store is still empty.
+
+        This test should follow a test that sets values.
 
         This just verifies that the fixture is set up properly to be empty
         after each test.
@@ -192,7 +194,9 @@ class BaseStoreAsyncTests(BaseStandardTests, Generic[V]):
         assert await kv_store.amget(["foo", "bar"]) == [foo, bar]
 
     async def test_store_still_empty(self, kv_store: BaseStore[str, V]) -> None:
-        """This test should follow a test that sets values.
+        """Test that the store is still empty.
+
+        This test should follow a test that sets values.
 
         This just verifies that the fixture is set up properly to be empty
         after each test.
diff --git a/libs/standard-tests/langchain_tests/integration_tests/cache.py b/libs/standard-tests/langchain_tests/integration_tests/cache.py
index 8856ff3bf69..18088612afa 100644
--- a/libs/standard-tests/langchain_tests/integration_tests/cache.py
+++ b/libs/standard-tests/langchain_tests/integration_tests/cache.py
@@ -62,7 +62,9 @@ class SyncCacheTestSuite(BaseStandardTests):
         assert cache.lookup(prompt, llm_string) == [generation]
 
     def test_cache_still_empty(self, cache: BaseCache) -> None:
-        """This test should follow a test that updates the cache.
+        """Test that the cache is still empty.
+
+        This test should follow a test that updates the cache.
 
         This just verifies that the fixture is set up properly to be empty
         after each test.
@@ -153,7 +155,9 @@ class AsyncCacheTestSuite(BaseStandardTests):
         assert await cache.alookup(prompt, llm_string) == [generation]
 
     async def test_cache_still_empty(self, cache: BaseCache) -> None:
-        """This test should follow a test that updates the cache.
+        """Test that the cache is still empty.
+
+        This test should follow a test that updates the cache.
 
         This just verifies that the fixture is set up properly to be empty
         after each test.
diff --git a/libs/standard-tests/langchain_tests/integration_tests/chat_models.py b/libs/standard-tests/langchain_tests/integration_tests/chat_models.py
index d6666ed55a6..1750e8bdefd 100644
--- a/libs/standard-tests/langchain_tests/integration_tests/chat_models.py
+++ b/libs/standard-tests/langchain_tests/integration_tests/chat_models.py
@@ -1,3 +1,5 @@
+"""Integration tests for chat models."""
+
 import base64
 import inspect
 import json
@@ -39,8 +41,6 @@ from langchain_tests.utils.pydantic import PYDANTIC_MAJOR_VERSION
 def _get_joke_class(
     schema_type: Literal["pydantic", "typeddict", "json_schema"],
 ) -> Any:
-    """:private:"""
-
     class Joke(BaseModel):
         """Joke to tell user."""
 
@@ -95,13 +95,13 @@ class _MagicFunctionSchema(BaseModel):
 
 @tool(args_schema=_MagicFunctionSchema)
 def magic_function(_input: int) -> int:
-    """Applies a magic function to an input."""
+    """Apply a magic function to an input."""
     return _input + 2
 
 
 @tool
 def magic_function_no_args() -> int:
-    """Calculates a magic function."""
+    """Calculate a magic function."""
     return 5
 
 
@@ -143,7 +143,7 @@ def unicode_customer(customer_name: str, description: str) -> str:
 
 
 class ChatModelIntegrationTests(ChatModelTests):
-    """Base class for chat model integration tests.
+    '''Base class for chat model integration tests.
 
     Test subclasses must implement the ``chat_model_class`` and
     ``chat_model_params`` properties to specify what model to test and its
@@ -587,7 +587,7 @@ class ChatModelIntegrationTests(ChatModelTests):
 
                 @pytest.fixture(scope="session")
                 def vcr_config(_base_vcr_config: dict) -> dict:  # noqa: F811
-                    \"\"\"Extend the default configuration from langchain_tests.\"\"\"
+                    """Extend the default configuration from langchain_tests."""
                     config = _base_vcr_config.copy()
                     config.setdefault("filter_headers", []).extend(_EXTRA_HEADERS)
                     config["before_record_response"] = remove_response_headers
@@ -623,7 +623,7 @@ class ChatModelIntegrationTests(ChatModelTests):
 
                     @pytest.fixture(scope="session")
                     def vcr_config(_base_vcr_config: dict) -> dict:  # noqa: F811
-                        \"\"\"Extend the default configuration from langchain_tests.\"\"\"
+                        """Extend the default configuration from langchain_tests."""
                         config = _base_vcr_config.copy()
                         config.setdefault("filter_headers", []).extend(_EXTRA_HEADERS)
                         config["before_record_response"] = remove_response_headers
@@ -675,11 +675,14 @@ class ChatModelIntegrationTests(ChatModelTests):
             You can then commit the cassette to your repository. Subsequent test runs
             will use the cassette instead of making HTTP calls.
 
-    """  # noqa: E501
+    '''  # noqa: E501,D214
 
     @property
     def standard_chat_model_params(self) -> dict:
-        """:private:"""
+        """Standard parameters for chat model.
+
+        :private:
+        """
         return {}
 
     def test_invoke(self, model: BaseChatModel) -> None:
@@ -1270,8 +1273,10 @@ class ChatModelIntegrationTests(ChatModelTests):
             )
 
     def test_stop_sequence(self, model: BaseChatModel) -> None:
-        """Test that model does not fail when invoked with the ``stop`` parameter,
-        which is a standard parameter for stopping generation at a certain token.
+        """Test that model does not fail when invoked with the ``stop`` parameter.
+
+        The ``stop`` parameter is a standard parameter for stopping generation at a
+        certain token.
 
         `More on standard parameters <https://python.langchain.com/docs/concepts/chat_models/#standard-parameters>`__
 
@@ -1306,8 +1311,10 @@ class ChatModelIntegrationTests(ChatModelTests):
         assert isinstance(result, AIMessage)
 
     def test_tool_calling(self, model: BaseChatModel) -> None:
-        """Test that the model generates tool calls. This test is skipped if the
-        ``has_tool_calling`` property on the test class is set to False.
+        """Test that the model generates tool calls.
+
+        This test is skipped if the ``has_tool_calling`` property on the test class is
+        set to False.
 
         This test is optional and should be skipped if the model does not support
         tool calling (see Configuration below).
@@ -1381,8 +1388,10 @@ class ChatModelIntegrationTests(ChatModelTests):
         _validate_tool_call_message(full)
 
     async def test_tool_calling_async(self, model: BaseChatModel) -> None:
-        """Test that the model generates tool calls. This test is skipped if the
-        ``has_tool_calling`` property on the test class is set to False.
+        """Test that the model generates tool calls.
+
+        This test is skipped if the ``has_tool_calling`` property on the test class is
+        set to False.
 
         This test is optional and should be skipped if the model does not support
         tool calling (see Configuration below).
@@ -1441,7 +1450,9 @@ class ChatModelIntegrationTests(ChatModelTests):
         _validate_tool_call_message(full)
 
     def test_bind_runnables_as_tools(self, model: BaseChatModel) -> None:
-        """Test that the model generates tool calls for tools that are derived from
+        """Test bind runnables as tools.
+
+        Test that the model generates tool calls for tools that are derived from
         LangChain runnables. This test is skipped if the ``has_tool_calling`` property
         on the test class is set to False.
 
@@ -1509,8 +1520,10 @@ class ChatModelIntegrationTests(ChatModelTests):
     def test_tool_message_histories_string_content(
         self, model: BaseChatModel, my_adder_tool: BaseTool
     ) -> None:
-        """Test that message histories are compatible with string tool contents
-        (e.g. OpenAI format). If a model passes this test, it should be compatible
+        """Test that message histories are compatible with string tool contents.
+
+        For instance with OpenAI format contents.
+        If a model passes this test, it should be compatible
         with messages generated from providers following OpenAI format.
 
         This test should be skipped if the model does not support tool calling
@@ -1581,8 +1594,9 @@ class ChatModelIntegrationTests(ChatModelTests):
         model: BaseChatModel,
         my_adder_tool: BaseTool,
     ) -> None:
-        """Test that message histories are compatible with list tool contents
-        (e.g. Anthropic format).
+        """Test that message histories are compatible with list tool contents.
+
+        For instance with Anthropic format contents.
 
         These message histories will include ``AIMessage`` objects with "tool use" and
         content blocks, e.g.,
@@ -1671,7 +1685,9 @@ class ChatModelIntegrationTests(ChatModelTests):
         assert isinstance(result_list_content, AIMessage)
 
     def test_tool_choice(self, model: BaseChatModel) -> None:
-        """Test that the model can force tool calling via the ``tool_choice``
+        """Test ``tool_choice`` parameter.
+
+        Test that the model can force tool calling via the ``tool_choice``
         parameter. This test is skipped if the ``has_tool_choice`` property on the
         test class is set to False.
 
@@ -1723,6 +1739,7 @@ class ChatModelIntegrationTests(ChatModelTests):
 
     def test_tool_calling_with_no_arguments(self, model: BaseChatModel) -> None:
         """Test that the model generates tool calls for tools with no arguments.
+
         This test is skipped if the ``has_tool_calling`` property on the test class
         is set to False.
 
@@ -2075,7 +2092,9 @@ class ChatModelIntegrationTests(ChatModelTests):
 
     @pytest.mark.skipif(PYDANTIC_MAJOR_VERSION != 2, reason="Test requires pydantic 2.")
     def test_structured_output_pydantic_2_v1(self, model: BaseChatModel) -> None:
-        """Test to verify we can generate structured output using ``pydantic.v1.BaseModel``.
+        """Test structured output using pydantic.v1.BaseModel.
+
+        Verify we can generate structured output using ``pydantic.v1.BaseModel``.
 
         ``pydantic.v1.BaseModel`` is available in the Pydantic 2 package.
 
@@ -2140,7 +2159,9 @@ class ChatModelIntegrationTests(ChatModelTests):
         assert set(chunk.keys()) == {"setup", "punchline"}
 
     def test_structured_output_optional_param(self, model: BaseChatModel) -> None:
-        """Test to verify we can generate structured output that includes optional
+        """Test structured output with optional parameters.
+
+        Test to verify we can generate structured output that includes optional
         parameters.
 
         This test is optional and should be skipped if the model does not support
@@ -2847,8 +2868,10 @@ class ChatModelIntegrationTests(ChatModelTests):
         assert len(result.content) > 0
 
     def test_agent_loop(self, model: BaseChatModel) -> None:
-        """Test that the model supports a simple ReAct agent loop. This test is skipped
-        if the ``has_tool_calling`` property on the test class is set to False.
+        """Test that the model supports a simple ReAct agent loop.
+
+        This test is skipped if the ``has_tool_calling`` property on the test class is
+        set to False.
 
         This test is optional and should be skipped if the model does not support
         tool calling (see Configuration below).
@@ -2953,23 +2976,38 @@ class ChatModelIntegrationTests(ChatModelTests):
             benchmark(_run)
 
     def invoke_with_audio_input(self, *, stream: bool = False) -> AIMessage:
-        """:private:"""
+        """Invoke with audio input.
+
+        :private:
+        """
         raise NotImplementedError
 
     def invoke_with_audio_output(self, *, stream: bool = False) -> AIMessage:
-        """:private:"""
+        """Invoke with audio output.
+
+        :private:
+        """
         raise NotImplementedError
 
     def invoke_with_reasoning_output(self, *, stream: bool = False) -> AIMessage:
-        """:private:"""
+        """Invoke with reasoning output.
+
+        :private:
+        """
         raise NotImplementedError
 
     def invoke_with_cache_read_input(self, *, stream: bool = False) -> AIMessage:
-        """:private:"""
+        """Invoke with cache read input.
+
+        :private:
+        """
         raise NotImplementedError
 
     def invoke_with_cache_creation_input(self, *, stream: bool = False) -> AIMessage:
-        """:private:"""
+        """Invoke with cache creation input.
+
+        :private:
+        """
         raise NotImplementedError
 
     def test_unicode_tool_call_integration(
@@ -2979,7 +3017,7 @@ class ChatModelIntegrationTests(ChatModelTests):
         tool_choice: Optional[str] = None,
         force_tool_call: bool = True,
     ) -> None:
-        """Generic integration test for Unicode characters in tool calls.
+        r"""Generic integration test for Unicode characters in tool calls.
 
         Args:
             model: The chat model to test
diff --git a/libs/standard-tests/langchain_tests/integration_tests/embeddings.py b/libs/standard-tests/langchain_tests/integration_tests/embeddings.py
index eb68a42eccc..9f35aa0bd5b 100644
--- a/libs/standard-tests/langchain_tests/integration_tests/embeddings.py
+++ b/libs/standard-tests/langchain_tests/integration_tests/embeddings.py
@@ -1,3 +1,5 @@
+"""Integration tests for embeddings."""
+
 from langchain_core.embeddings import Embeddings
 
 from langchain_tests.unit_tests.embeddings import EmbeddingsTests
diff --git a/libs/standard-tests/langchain_tests/integration_tests/retrievers.py b/libs/standard-tests/langchain_tests/integration_tests/retrievers.py
index 3c024016097..204134e31a4 100644
--- a/libs/standard-tests/langchain_tests/integration_tests/retrievers.py
+++ b/libs/standard-tests/langchain_tests/integration_tests/retrievers.py
@@ -1,3 +1,5 @@
+"""Integration tests for retrievers."""
+
 from abc import abstractmethod
 
 import pytest
@@ -37,7 +39,10 @@ class RetrieversIntegrationTests(BaseStandardTests):
 
     @pytest.fixture
     def retriever(self) -> BaseRetriever:
-        """:private:"""
+        """Return retriever fixture.
+
+        :private:
+        """
         return self.retriever_constructor(**self.retriever_constructor_params)
 
     def test_k_constructor_param(self) -> None:
@@ -148,7 +153,9 @@ class RetrieversIntegrationTests(BaseStandardTests):
         assert all(isinstance(doc, Document) for doc in result_3)
 
     def test_invoke_returns_documents(self, retriever: BaseRetriever) -> None:
-        """If invoked with the example params, the retriever should return a list of
+        """Test invoke returns documents.
+
+        If invoked with the example params, the retriever should return a list of
         Documents.
 
         .. dropdown:: Troubleshooting
@@ -163,7 +170,9 @@ class RetrieversIntegrationTests(BaseStandardTests):
         assert all(isinstance(doc, Document) for doc in result)
 
     async def test_ainvoke_returns_documents(self, retriever: BaseRetriever) -> None:
-        """If ainvoked with the example params, the retriever should return a list of
+        """Test ainvoke returns documents.
+
+        If ainvoked with the example params, the retriever should return a list of
         Documents.
 
         See :meth:`test_invoke_returns_documents` for more information on
diff --git a/libs/standard-tests/langchain_tests/integration_tests/tools.py b/libs/standard-tests/langchain_tests/integration_tests/tools.py
index e21772b8928..03915105e5f 100644
--- a/libs/standard-tests/langchain_tests/integration_tests/tools.py
+++ b/libs/standard-tests/langchain_tests/integration_tests/tools.py
@@ -1,3 +1,5 @@
+"""Integration tests for tools."""
+
 from langchain_core.messages import ToolCall
 from langchain_core.tools import BaseTool
 
@@ -66,7 +68,9 @@ class ToolsIntegrationTests(ToolsTests):
             assert all(isinstance(c, (str, dict)) for c in tool_message.content)
 
     def test_invoke_no_tool_call(self, tool: BaseTool) -> None:
-        """If invoked without a ToolCall, the tool can return anything
+        """Test invoke without ToolCall.
+
+        If invoked without a ToolCall, the tool can return anything
         but it shouldn't throw an error.
 
         If this test fails, your tool may not be handling the input you defined
@@ -78,7 +82,9 @@ class ToolsIntegrationTests(ToolsTests):
         tool.invoke(self.tool_invoke_params_example)
 
     async def test_async_invoke_no_tool_call(self, tool: BaseTool) -> None:
-        """If ainvoked without a ToolCall, the tool can return anything
+        """Test async invoke without ToolCall.
+
+        If ainvoked without a ToolCall, the tool can return anything
         but it shouldn't throw an error.
 
         For debugging tips, see :meth:`test_invoke_no_tool_call`.
diff --git a/libs/standard-tests/langchain_tests/integration_tests/vectorstores.py b/libs/standard-tests/langchain_tests/integration_tests/vectorstores.py
index acb6960d5c0..96088a552cb 100644
--- a/libs/standard-tests/langchain_tests/integration_tests/vectorstores.py
+++ b/libs/standard-tests/langchain_tests/integration_tests/vectorstores.py
@@ -116,7 +116,9 @@ class VectorStoreIntegrationTests(BaseStandardTests):
 
     @staticmethod
     def get_embeddings() -> Embeddings:
-        """A pre-defined embeddings model that should be used for this test.
+        """Get embeddings.
+
+        A pre-defined embeddings model that should be used for this test.
 
         This currently uses ``DeterministicFakeEmbedding`` from ``langchain-core``,
         which uses numpy to generate random numbers based on a hash of the input text.
@@ -173,7 +175,9 @@ class VectorStoreIntegrationTests(BaseStandardTests):
         ]
 
     def test_vectorstore_still_empty(self, vectorstore: VectorStore) -> None:
-        """This test should follow a test that adds documents.
+        """Test that the vectorstore is still empty.
+
+        This test should follow a test that adds documents.
 
         This just verifies that the fixture is set up properly to be empty
         after each test.
@@ -499,7 +503,9 @@ class VectorStoreIntegrationTests(BaseStandardTests):
     async def test_vectorstore_still_empty_async(
         self, vectorstore: VectorStore
     ) -> None:
-        """This test should follow a test that adds documents.
+        """Test that the vectorstore is still empty.
+
+        This test should follow a test that adds documents.
 
         This just verifies that the fixture is set up properly to be empty
         after each test.
diff --git a/libs/standard-tests/langchain_tests/unit_tests/__init__.py b/libs/standard-tests/langchain_tests/unit_tests/__init__.py
index ee4a1700eda..5ba211de31e 100644
--- a/libs/standard-tests/langchain_tests/unit_tests/__init__.py
+++ b/libs/standard-tests/langchain_tests/unit_tests/__init__.py
@@ -1,3 +1,5 @@
+"""Unit tests for LangChain components."""
+
 # ruff: noqa: E402
 import pytest
 
diff --git a/libs/standard-tests/langchain_tests/unit_tests/chat_models.py b/libs/standard-tests/langchain_tests/unit_tests/chat_models.py
index a42201f2bce..0c3b038df8d 100644
--- a/libs/standard-tests/langchain_tests/unit_tests/chat_models.py
+++ b/libs/standard-tests/langchain_tests/unit_tests/chat_models.py
@@ -83,7 +83,10 @@ class ChatModelTests(BaseStandardTests):
 
     @property
     def standard_chat_model_params(self) -> dict:
-        """:private:"""
+        """Standard chat model parameters.
+
+        :private:
+        """
         return {
             "temperature": 0,
             "max_tokens": 100,
@@ -94,7 +97,10 @@ class ChatModelTests(BaseStandardTests):
 
     @pytest.fixture
     def model(self) -> BaseChatModel:
-        """:private:"""
+        """Model fixture.
+
+        :private:
+        """
         return self.chat_model_class(
             **{
                 **self.standard_chat_model_params,
@@ -104,11 +110,17 @@ class ChatModelTests(BaseStandardTests):
 
     @pytest.fixture
     def my_adder_tool(self) -> BaseTool:
-        """:private:"""
+        """Adder tool fixture.
+
+        :private:
+        """
 
         @tool
         def my_adder_tool(a: int, b: int) -> int:
-            """Takes two integers, a and b, and returns their sum."""
+            """Tool that adds two integers.
+
+            Takes two integers, a and b, and returns their sum.
+            """
             return a + b
 
         return my_adder_tool
@@ -151,12 +163,22 @@ class ChatModelTests(BaseStandardTests):
 
     @property
     def supports_image_inputs(self) -> bool:
-        """(bool) whether the chat model supports image inputs, defaults to ``False``."""  # noqa: E501
+        """Supports image inputs.
+
+        (bool) whether the chat model supports image inputs, defaults to
+        ``False``.
+
+        """
         return False
 
     @property
     def supports_image_urls(self) -> bool:
-        """(bool) whether the chat model supports image inputs from URLs, defaults to ``False``."""  # noqa: E501
+        """Supports image inputs from URLs.
+
+        (bool) whether the chat model supports image inputs from URLs, defaults to
+        ``False``.
+
+        """
         return False
 
     @property
@@ -166,12 +188,18 @@ class ChatModelTests(BaseStandardTests):
 
     @property
     def supports_audio_inputs(self) -> bool:
-        """(bool) whether the chat model supports audio inputs, defaults to ``False``."""  # noqa: E501
+        """Supports audio inputs.
+
+        (bool) whether the chat model supports audio inputs, defaults to ``False``.
+
+        """
         return False
 
     @property
     def supports_video_inputs(self) -> bool:
-        """(bool) whether the chat model supports video inputs, defaults to ``False``.
+        """Supports video inputs.
+
+        (bool) whether the chat model supports video inputs, defaults to ``False``.
 
         No current tests are written for this feature.
 
@@ -180,7 +208,12 @@ class ChatModelTests(BaseStandardTests):
 
     @property
     def returns_usage_metadata(self) -> bool:
-        """(bool) whether the chat model returns usage metadata on invoke and streaming responses."""  # noqa: E501
+        """Returns usage metadata.
+
+        (bool) whether the chat model returns usage metadata on invoke and streaming
+        responses.
+
+        """
         return True
 
     @property
@@ -190,7 +223,12 @@ class ChatModelTests(BaseStandardTests):
 
     @property
     def supports_image_tool_message(self) -> bool:
-        """(bool) whether the chat model supports ``ToolMessage``s that include image content."""  # noqa: E501
+        """Supports image ToolMessages.
+
+        (bool) whether the chat model supports ToolMessages that include image
+        content.
+
+        """
         return False
 
     @property
@@ -219,14 +257,16 @@ class ChatModelTests(BaseStandardTests):
             ]
         ],
     ]:
-        """(dict) what usage metadata details are emitted in invoke and stream. Only
+        """Supported usage metadata details.
+
+        (dict) what usage metadata details are emitted in invoke and stream. Only
         needs to be overridden if these details are returned by the model.
         """
         return {"invoke": [], "stream": []}
 
 
 class ChatModelUnitTests(ChatModelTests):
-    """Base class for chat model unit tests.
+    '''Base class for chat model unit tests.
 
     Test subclasses must implement the ``chat_model_class`` and
     ``chat_model_params`` properties to specify what model to test and its
@@ -669,7 +709,7 @@ class ChatModelUnitTests(ChatModelTests):
 
                 @pytest.fixture(scope="session")
                 def vcr_config(_base_vcr_config: dict) -> dict:  # noqa: F811
-                    \"\"\"Extend the default configuration from langchain_tests.\"\"\"
+                    """Extend the default configuration from langchain_tests."""
                     config = _base_vcr_config.copy()
                     config.setdefault("filter_headers", []).extend(_EXTRA_HEADERS)
                     config["before_record_response"] = remove_response_headers
@@ -705,7 +745,7 @@ class ChatModelUnitTests(ChatModelTests):
 
                     @pytest.fixture(scope="session")
                     def vcr_config(_base_vcr_config: dict) -> dict:  # noqa: F811
-                        \"\"\"Extend the default configuration from langchain_tests.\"\"\"
+                        """Extend the default configuration from langchain_tests."""
                         config = _base_vcr_config.copy()
                         config.setdefault("filter_headers", []).extend(_EXTRA_HEADERS)
                         config["before_record_response"] = remove_response_headers
@@ -789,18 +829,23 @@ class ChatModelUnitTests(ChatModelTests):
                         },
                     )
 
-    """  # noqa: E501
+    '''  # noqa: E501,D214
 
     @property
     def standard_chat_model_params(self) -> dict:
-        """:private:"""
+        """Standard chat model parameters.
+
+        :private:
+        """
         params = super().standard_chat_model_params
         params["api_key"] = "test"
         return params
 
     @property
     def init_from_env_params(self) -> tuple[dict, dict, dict]:
-        """(tuple) environment variables, additional initialization args, and expected
+        """Init from env params.
+
+        (tuple) environment variables, additional initialization args, and expected
         instance attributes for testing initialization from environment variables.
 
         """
@@ -826,9 +871,10 @@ class ChatModelUnitTests(ChatModelTests):
         assert model is not None
 
     def test_init_from_env(self) -> None:
-        """Test initialization from environment variables. Relies on the
-        ``init_from_env_params`` property. Test is skipped if that property is not
-        set.
+        """Test initialization from environment variables.
+
+        Relies on the ``init_from_env_params`` property. Test is skipped if that
+        property is not set.
 
         .. dropdown:: Troubleshooting
 
@@ -853,8 +899,9 @@ class ChatModelUnitTests(ChatModelTests):
     def test_init_streaming(
         self,
     ) -> None:
-        """Test that model can be initialized with ``streaming=True``. This is for
-        backward-compatibility purposes.
+        """Test that model can be initialized with ``streaming=True``.
+
+        This is for backward-compatibility purposes.
 
         .. dropdown:: Troubleshooting
 
@@ -876,7 +923,9 @@ class ChatModelUnitTests(ChatModelTests):
         model: BaseChatModel,
         my_adder_tool: BaseTool,
     ) -> None:
-        """Test that chat model correctly handles Pydantic models that are passed
+        """Test bind tools with Pydantic models.
+
+        Test that chat model correctly handles Pydantic models that are passed
         into ``bind_tools``. Test is skipped if the ``has_tool_calling`` property
         on the test class is False.
 
@@ -893,7 +942,7 @@ class ChatModelUnitTests(ChatModelTests):
             return
 
         def my_adder(a: int, b: int) -> int:
-            """Takes two integers, a and b, and returns their sum."""
+            """Return the sum of two integers."""
             return a + b
 
         tools = [my_adder_tool, my_adder]
@@ -918,8 +967,10 @@ class ChatModelUnitTests(ChatModelTests):
         model: BaseChatModel,
         schema: Any,
     ) -> None:
-        """Test ``with_structured_output`` method. Test is skipped if the
-        ``has_structured_output`` property on the test class is False.
+        """Test ``with_structured_output`` method.
+
+        Test is skipped if the ``has_structured_output`` property on the test class is
+        False.
 
         .. dropdown:: Troubleshooting
 
@@ -942,8 +993,9 @@ class ChatModelUnitTests(ChatModelTests):
                 )
 
     def test_standard_params(self, model: BaseChatModel) -> None:
-        """Test that model properly generates standard parameters. These are used
-        for tracing purposes.
+        """Test that model properly generates standard parameters.
+
+        These are used for tracing purposes.
 
         .. dropdown:: Troubleshooting
 
@@ -981,9 +1033,10 @@ class ChatModelUnitTests(ChatModelTests):
             pytest.fail(f"Validation error: {e}")
 
     def test_serdes(self, model: BaseChatModel, snapshot: SnapshotAssertion) -> None:
-        """Test serialization and deserialization of the model. Test is skipped if the
-        ``is_lc_serializable`` property on the chat model class is not overwritten
-        to return ``True``.
+        """Test serialization and deserialization of the model.
+
+        Test is skipped if the ``is_lc_serializable`` property on the chat model class
+        is not overwritten to return ``True``.
 
         .. dropdown:: Troubleshooting
 
@@ -1007,7 +1060,9 @@ class ChatModelUnitTests(ChatModelTests):
 
     @pytest.mark.benchmark
     def test_init_time(self, benchmark: BenchmarkFixture) -> None:
-        """Test initialization time of the chat model. If this test fails, check that
+        """Test initialization time of the chat model.
+
+        If this test fails, check that
         we are not introducing undue overhead in the model's initialization.
 
         """
diff --git a/libs/standard-tests/langchain_tests/unit_tests/embeddings.py b/libs/standard-tests/langchain_tests/unit_tests/embeddings.py
index 0df698ee8bd..a1693b497a3 100644
--- a/libs/standard-tests/langchain_tests/unit_tests/embeddings.py
+++ b/libs/standard-tests/langchain_tests/unit_tests/embeddings.py
@@ -1,3 +1,5 @@
+"""Embeddings unit tests."""
+
 import os
 from abc import abstractmethod
 from unittest import mock
@@ -10,18 +12,24 @@ from langchain_tests.base import BaseStandardTests
 
 
 class EmbeddingsTests(BaseStandardTests):
-    """:private:"""
+    """Embeddings tests base class.
+
+    :private:
+    """
 
     @property
     @abstractmethod
-    def embeddings_class(self) -> type[Embeddings]: ...
+    def embeddings_class(self) -> type[Embeddings]:
+        """Embeddings class."""
 
     @property
     def embedding_model_params(self) -> dict:
+        """Embeddings model parameters."""
         return {}
 
     @pytest.fixture
     def model(self) -> Embeddings:
+        """Embeddings model fixture."""
         return self.embeddings_class(**self.embedding_model_params)
 
 
@@ -87,7 +95,7 @@ class EmbeddingsUnitTests(EmbeddingsTests):
                         },
                     )
 
-    """
+    """  # noqa: D214
 
     def test_init(self) -> None:
         """Test model initialization.
@@ -102,7 +110,9 @@ class EmbeddingsUnitTests(EmbeddingsTests):
 
     @property
     def init_from_env_params(self) -> tuple[dict, dict, dict]:
-        """This property is used in unit tests to test initialization from environment
+        """Init from env params.
+
+        This property is used in unit tests to test initialization from environment
         variables. It should return a tuple of three dictionaries that specify the
         environment variables, additional initialization args, and expected instance
         attributes to check.
@@ -110,9 +120,10 @@ class EmbeddingsUnitTests(EmbeddingsTests):
         return {}, {}, {}
 
     def test_init_from_env(self) -> None:
-        """Test initialization from environment variables. Relies on the
-        ``init_from_env_params`` property. Test is skipped if that property is not
-        set.
+        """Test initialization from environment variables.
+
+        Relies on the ``init_from_env_params`` property.
+        Test is skipped if that property is not set.
 
         .. dropdown:: Troubleshooting
 
diff --git a/libs/standard-tests/langchain_tests/unit_tests/tools.py b/libs/standard-tests/langchain_tests/unit_tests/tools.py
index cbc40dc4121..fb59a2065c6 100644
--- a/libs/standard-tests/langchain_tests/unit_tests/tools.py
+++ b/libs/standard-tests/langchain_tests/unit_tests/tools.py
@@ -1,3 +1,5 @@
+"""Tools unit tests."""
+
 import os
 from abc import abstractmethod
 from typing import Union
@@ -11,9 +13,11 @@ from langchain_tests.base import BaseStandardTests
 
 
 class ToolsTests(BaseStandardTests):
-    """:private:
-    Base class for testing tools. This won't show in the documentation, but
-    the docstrings will be inherited by subclasses.
+    """Base class for testing tools.
+
+    :private:
+    This won't show in the documentation, but the docstrings will be inherited by
+    subclasses.
     """
 
     @property
@@ -38,7 +42,10 @@ class ToolsTests(BaseStandardTests):
 
     @pytest.fixture
     def tool(self) -> BaseTool:
-        """:private:"""
+        """Tool fixture.
+
+        :private:
+        """
         if isinstance(self.tool_constructor, BaseTool):
             if self.tool_constructor_params != {}:
                 msg = (
@@ -55,13 +62,17 @@ class ToolsUnitTests(ToolsTests):
 
     @property
     def init_from_env_params(self) -> tuple[dict, dict, dict]:
-        """Return env vars, init args, and expected instance attrs for initializing
+        """Init from env params.
+
+        Return env vars, init args, and expected instance attrs for initializing
         from env vars.
         """
         return {}, {}, {}
 
     def test_init(self) -> None:
-        """Test that the tool can be initialized with :attr:`tool_constructor` and
+        """Test init.
+
+        Test that the tool can be initialized with :attr:`tool_constructor` and
         :attr:`tool_constructor_params`. If this fails, check that the
         keyword args defined in :attr:`tool_constructor_params` are valid.
         """
@@ -72,6 +83,7 @@ class ToolsUnitTests(ToolsTests):
         assert tool is not None
 
     def test_init_from_env(self) -> None:
+        """Test that the tool can be initialized from environment variables."""
         env_params, tools_params, expected_attrs = self.init_from_env_params
         if env_params:
             with mock.patch.dict(os.environ, env_params):
diff --git a/libs/standard-tests/langchain_tests/utils/__init__.py b/libs/standard-tests/langchain_tests/utils/__init__.py
index e69de29bb2d..a320431fc87 100644
--- a/libs/standard-tests/langchain_tests/utils/__init__.py
+++ b/libs/standard-tests/langchain_tests/utils/__init__.py
@@ -0,0 +1 @@
+"""Langchain tests utilities."""
diff --git a/libs/standard-tests/pyproject.toml b/libs/standard-tests/pyproject.toml
index f30b8b37c71..2c50bd11c09 100644
--- a/libs/standard-tests/pyproject.toml
+++ b/libs/standard-tests/pyproject.toml
@@ -55,9 +55,12 @@ ignore_missing_imports = true
 target-version = "py39"
 
 [tool.ruff.lint]
-select = ["E", "F", "I", "PGH", "T201", "UP",]
+select = ["D", "E", "F", "I", "PGH", "T201", "UP",]
 pyupgrade.keep-runtime-typing = true
 
+[tool.ruff.lint.per-file-ignores]
+"tests/**" = [ "D1",]
+
 [tool.coverage.run]
 omit = ["tests/*"]
 
diff --git a/libs/standard-tests/scripts/check_imports.py b/libs/standard-tests/scripts/check_imports.py
index fb5a5641fef..47360d73bb2 100644
--- a/libs/standard-tests/scripts/check_imports.py
+++ b/libs/standard-tests/scripts/check_imports.py
@@ -1,3 +1,5 @@
+"""Check imports script."""
+
 import secrets
 import string
 import sys
diff --git a/libs/standard-tests/tests/unit_tests/custom_chat_model.py b/libs/standard-tests/tests/unit_tests/custom_chat_model.py
index 737745ec27e..d8f9f7c668f 100644
--- a/libs/standard-tests/tests/unit_tests/custom_chat_model.py
+++ b/libs/standard-tests/tests/unit_tests/custom_chat_model.py
@@ -10,7 +10,9 @@ from pydantic import Field
 
 
 class ChatParrotLink(BaseChatModel):
-    """A custom chat model that echoes the first `parrot_buffer_length` characters
+    """Chat Parrot Link.
+
+    A custom chat model that echoes the first `parrot_buffer_length` characters
     of the input.
 
     When contributing an implementation to LangChain, carefully document
@@ -60,6 +62,8 @@ class ChatParrotLink(BaseChatModel):
                   it makes it much easier to parse the output of the model
                   downstream and understand why generation stopped.
             run_manager: A run manager with callbacks for the LLM.
+            **kwargs: Additional keyword arguments.
+
         """
         # Replace this with actual logic to generate a response from a list
         # of messages.
@@ -111,6 +115,8 @@ class ChatParrotLink(BaseChatModel):
                   it makes it much easier to parse the output of the model
                   downstream and understand why generation stopped.
             run_manager: A run manager with callbacks for the LLM.
+            **kwargs: Additional keyword arguments.
+
         """
         _ = stop  # Mark as used to avoid unused variable warning
         _ = kwargs  # Mark as used to avoid unused variable warning