diff --git a/langchain/agents/agent_toolkits/base.py b/langchain/agents/agent_toolkits/base.py
index ce9b9e43af9..0cb78d1de8b 100644
--- a/langchain/agents/agent_toolkits/base.py
+++ b/langchain/agents/agent_toolkits/base.py
@@ -1,5 +1,5 @@
 """Toolkits for agents."""
-from abc import abstractmethod
+from abc import ABC, abstractmethod
 from typing import List
 
 from pydantic import BaseModel
@@ -7,8 +7,8 @@ from pydantic import BaseModel
 from langchain.tools import BaseTool
 
 
-class BaseToolkit(BaseModel):
-    """Class responsible for defining a collection of related tools."""
+class BaseToolkit(BaseModel, ABC):
+    """Class representing a collection of related tools."""
 
     @abstractmethod
     def get_tools(self) -> List[BaseTool]:
diff --git a/langchain/agents/agent_toolkits/csv/base.py b/langchain/agents/agent_toolkits/csv/base.py
index ac1b2501197..dbda4be8baf 100644
--- a/langchain/agents/agent_toolkits/csv/base.py
+++ b/langchain/agents/agent_toolkits/csv/base.py
@@ -1,4 +1,4 @@
-"""Agent for working with csvs."""
+"""Agent for working with csv files."""
 from typing import Any, List, Optional, Union
 
 from langchain.agents.agent import AgentExecutor
diff --git a/langchain/agents/agent_toolkits/office365/__init__.py b/langchain/agents/agent_toolkits/office365/__init__.py
index 02e7f81659f..acd0a87f955 100644
--- a/langchain/agents/agent_toolkits/office365/__init__.py
+++ b/langchain/agents/agent_toolkits/office365/__init__.py
@@ -1 +1 @@
-"""Gmail toolkit."""
+"""Office365 toolkit."""
diff --git a/langchain/agents/agent_toolkits/openapi/toolkit.py b/langchain/agents/agent_toolkits/openapi/toolkit.py
index 8c10dad8980..9c243cf72bf 100644
--- a/langchain/agents/agent_toolkits/openapi/toolkit.py
+++ b/langchain/agents/agent_toolkits/openapi/toolkit.py
@@ -39,7 +39,7 @@ class RequestsToolkit(BaseToolkit):
 
 
 class OpenAPIToolkit(BaseToolkit):
-    """Toolkit for interacting with a OpenAPI api."""
+    """Toolkit for interacting with an OpenAPI API."""
 
     json_agent: AgentExecutor
     requests_wrapper: TextRequestsWrapper
diff --git a/langchain/agents/agent_toolkits/powerbi/base.py b/langchain/agents/agent_toolkits/powerbi/base.py
index 3595f547c3c..62fed35c14b 100644
--- a/langchain/agents/agent_toolkits/powerbi/base.py
+++ b/langchain/agents/agent_toolkits/powerbi/base.py
@@ -17,7 +17,7 @@ from langchain.utilities.powerbi import PowerBIDataset
 
 def create_pbi_agent(
     llm: BaseLanguageModel,
-    toolkit: Optional[PowerBIToolkit],
+    toolkit: Optional[PowerBIToolkit] = None,
     powerbi: Optional[PowerBIDataset] = None,
     callback_manager: Optional[BaseCallbackManager] = None,
     prefix: str = POWERBI_PREFIX,
diff --git a/langchain/agents/agent_toolkits/powerbi/chat_base.py b/langchain/agents/agent_toolkits/powerbi/chat_base.py
index ff4c73301f1..a30d013f3a1 100644
--- a/langchain/agents/agent_toolkits/powerbi/chat_base.py
+++ b/langchain/agents/agent_toolkits/powerbi/chat_base.py
@@ -18,7 +18,7 @@ from langchain.utilities.powerbi import PowerBIDataset
 
 def create_pbi_chat_agent(
     llm: BaseChatModel,
-    toolkit: Optional[PowerBIToolkit],
+    toolkit: Optional[PowerBIToolkit] = None,
     powerbi: Optional[PowerBIDataset] = None,
     callback_manager: Optional[BaseCallbackManager] = None,
     output_parser: Optional[AgentOutputParser] = None,
@@ -32,9 +32,9 @@ def create_pbi_chat_agent(
     agent_executor_kwargs: Optional[Dict[str, Any]] = None,
     **kwargs: Dict[str, Any],
 ) -> AgentExecutor:
-    """Construct a pbi agent from an Chat LLM and tools.
+    """Construct a Power BI agent from a Chat LLM and tools.
 
-    If you supply only a toolkit and no powerbi dataset, the same LLM is used for both.
+    If you supply only a toolkit and no Power BI dataset, the same LLM is used for both.
     """
     if toolkit is None:
         if powerbi is None:
diff --git a/langchain/agents/chat/output_parser.py b/langchain/agents/chat/output_parser.py
index c7023426aa0..6f1cda0ce2c 100644
--- a/langchain/agents/chat/output_parser.py
+++ b/langchain/agents/chat/output_parser.py
@@ -30,9 +30,8 @@ class ChatOutputParser(AgentOutputParser):
         except Exception:
             if not includes_answer:
                 raise OutputParserException(f"Could not parse LLM output: {text}")
-            return AgentFinish(
-                {"output": text.split(FINAL_ANSWER_ACTION)[-1].strip()}, text
-            )
+            output = text.split(FINAL_ANSWER_ACTION)[-1].strip()
+            return AgentFinish({"output": output}, text)
 
     @property
     def _type(self) -> str:
diff --git a/langchain/agents/self_ask_with_search/base.py b/langchain/agents/self_ask_with_search/base.py
index e63322fc0d6..2ddff23a85e 100644
--- a/langchain/agents/self_ask_with_search/base.py
+++ b/langchain/agents/self_ask_with_search/base.py
@@ -1,4 +1,4 @@
-"""Chain that does self ask with search."""
+"""Chain that does self-ask with search."""
 from typing import Any, Sequence, Union
 
 from pydantic import Field
@@ -59,7 +59,7 @@ class SelfAskWithSearchAgent(Agent):
 
 
 class SelfAskWithSearchChain(AgentExecutor):
-    """Chain that does self ask with search.
+    """Chain that does self-ask with search.
 
     Example:
         .. code-block:: python
diff --git a/langchain/callbacks/file.py b/langchain/callbacks/file.py
index 77edb879c74..7c132953645 100644
--- a/langchain/callbacks/file.py
+++ b/langchain/callbacks/file.py
@@ -39,7 +39,7 @@ class FileCallbackHandler(BaseCallbackHandler):
         self, action: AgentAction, color: Optional[str] = None, **kwargs: Any
     ) -> Any:
         """Run on agent action."""
-        print_text(action.log, color=color if color else self.color, file=self.file)
+        print_text(action.log, color=color or self.color, file=self.file)
 
     def on_tool_end(
         self,
@@ -52,24 +52,18 @@ class FileCallbackHandler(BaseCallbackHandler):
         """If not the final action, print out observation."""
         if observation_prefix is not None:
             print_text(f"\n{observation_prefix}", file=self.file)
-        print_text(output, color=color if color else self.color, file=self.file)
+        print_text(output, color=color or self.color, file=self.file)
         if llm_prefix is not None:
             print_text(f"\n{llm_prefix}", file=self.file)
 
     def on_text(
-        self,
-        text: str,
-        color: Optional[str] = None,
-        end: str = "",
-        **kwargs: Any,
+        self, text: str, color: Optional[str] = None, end: str = "", **kwargs: Any
     ) -> None:
         """Run when agent ends."""
-        print_text(text, color=color if color else self.color, end=end, file=self.file)
+        print_text(text, color=color or self.color, end=end, file=self.file)
 
     def on_agent_finish(
         self, finish: AgentFinish, color: Optional[str] = None, **kwargs: Any
     ) -> None:
         """Run on agent end."""
-        print_text(
-            finish.log, color=color if self.color else color, end="\n", file=self.file
-        )
+        print_text(finish.log, color=color or self.color, end="\n", file=self.file)
diff --git a/langchain/callbacks/stdout.py b/langchain/callbacks/stdout.py
index f87fdfb46a9..baa03de521f 100644
--- a/langchain/callbacks/stdout.py
+++ b/langchain/callbacks/stdout.py
@@ -63,7 +63,7 @@ class StdOutCallbackHandler(BaseCallbackHandler):
         self, action: AgentAction, color: Optional[str] = None, **kwargs: Any
     ) -> Any:
         """Run on agent action."""
-        print_text(action.log, color=color if color else self.color)
+        print_text(action.log, color=color or self.color)
 
     def on_tool_end(
         self,
@@ -76,7 +76,7 @@ class StdOutCallbackHandler(BaseCallbackHandler):
         """If not the final action, print out observation."""
         if observation_prefix is not None:
             print_text(f"\n{observation_prefix}")
-        print_text(output, color=color if color else self.color)
+        print_text(output, color=color or self.color)
         if llm_prefix is not None:
             print_text(f"\n{llm_prefix}")
 
@@ -94,10 +94,10 @@ class StdOutCallbackHandler(BaseCallbackHandler):
         **kwargs: Any,
     ) -> None:
         """Run when agent ends."""
-        print_text(text, color=color if color else self.color, end=end)
+        print_text(text, color=color or self.color, end=end)
 
     def on_agent_finish(
         self, finish: AgentFinish, color: Optional[str] = None, **kwargs: Any
     ) -> None:
         """Run on agent end."""
-        print_text(finish.log, color=color if self.color else color, end="\n")
+        print_text(finish.log, color=color or self.color, end="\n")
diff --git a/langchain/callbacks/streaming_stdout_final_only.py b/langchain/callbacks/streaming_stdout_final_only.py
index 0527db3598a..ba9e7da59f7 100644
--- a/langchain/callbacks/streaming_stdout_final_only.py
+++ b/langchain/callbacks/streaming_stdout_final_only.py
@@ -37,7 +37,7 @@ class FinalStreamingStdOutCallbackHandler(StreamingStdOutCallbackHandler):
         """Instantiate FinalStreamingStdOutCallbackHandler.
 
         Args:
-            answer_prefix_tokens: Token sequence that prefixes the anwer.
+            answer_prefix_tokens: Token sequence that prefixes the answer.
                 Default is ["Final", "Answer", ":"]
             strip_tokens: Ignore white spaces and new lines when comparing
                 answer_prefix_tokens to last tokens? (to determine if answer has been