diff --git a/.github/actions/people/action.yml b/.github/actions/people/action.yml
index a517c496a15..718a244dab6 100644
--- a/.github/actions/people/action.yml
+++ b/.github/actions/people/action.yml
@@ -1,4 +1,6 @@
 # Adapted from https://github.com/tiangolo/fastapi/blob/master/.github/actions/people/action.yml
+# TODO: fix this, migrate to new docs repo?
+
 name: "Generate LangChain People"
 description: "Generate the data for the LangChain People page"
 author: "Jacob Lee <jacob@langchain.dev>"
diff --git a/.github/actions/uv_setup/action.yml b/.github/actions/uv_setup/action.yml
index bf4a8689cd5..1d701d74282 100644
--- a/.github/actions/uv_setup/action.yml
+++ b/.github/actions/uv_setup/action.yml
@@ -1,3 +1,5 @@
+# Helper to set up Python and uv with caching
+
 name: uv-install
 description: Set up Python and uv with caching
 
@@ -8,15 +10,15 @@ inputs:
   enable-cache:
     description: Enable caching for uv dependencies
     required: false
-    default: 'true'
+    default: "true"
   cache-suffix:
     description: Custom cache key suffix for cache invalidation
     required: false
-    default: ''
+    default: ""
   working-directory:
     description: Working directory for cache glob scoping
     required: false
-    default: '**'
+    default: "**"
 
 env:
   UV_VERSION: "0.5.25"
diff --git a/.github/labeler.yml b/.github/pr-file-labeler.yml
similarity index 97%
rename from .github/labeler.yml
rename to .github/pr-file-labeler.yml
index 7ffab69b364..46d27024d73 100644
--- a/.github/labeler.yml
+++ b/.github/pr-file-labeler.yml
@@ -1,4 +1,4 @@
-# GitHub PR Labeler Configuration for LangChain
+# Label PRs (config)
 # Automatically applies labels based on changed files and branch patterns
 
 # Core packages
diff --git a/.github/pr-title-labeler.yml b/.github/pr-title-labeler.yml
index 0b78e4113a7..273456cb642 100644
--- a/.github/pr-title-labeler.yml
+++ b/.github/pr-title-labeler.yml
@@ -1,5 +1,7 @@
-# PR Title Labeler Configuration
+# PR title labeler config
+#
 # Labels PRs based on conventional commit patterns in titles
+#
 # Format: type(scope): description or type!: description (breaking)
 
 add-missing-labels: true
diff --git a/.github/scripts/check_diff.py b/.github/scripts/check_diff.py
index 4cf7e6415ea..cab7d153ac3 100644
--- a/.github/scripts/check_diff.py
+++ b/.github/scripts/check_diff.py
@@ -1,3 +1,18 @@
+"""Analyze git diffs to determine which directories need to be tested.
+
+Intelligently determines which LangChain packages and directories need to be tested,
+linted, or built based on the changes. Handles dependency relationships between
+packages, maps file changes to appropriate CI job configurations, and outputs JSON
+configurations for GitHub Actions.
+
+- Maps changed files to affected package directories (libs/core, libs/partners/*, etc.)
+- Builds dependency graph to include dependent packages when core components change
+- Generates test matrix configurations with appropriate Python versions
+- Handles special cases for Pydantic version testing and performance benchmarks
+
+Used as part of the check_diffs workflow.
+"""
+
 import glob
 import json
 import os
@@ -17,7 +32,7 @@ LANGCHAIN_DIRS = [
     "libs/langchain_v1",
 ]
 
-# when set to True, we are ignoring core dependents
+# When set to True, we are ignoring core dependents
 # in order to be able to get CI to pass for each individual
 # package that depends on core
 # e.g. if you touch core, we don't then add textsplitters/etc to CI
@@ -49,9 +64,9 @@ def all_package_dirs() -> Set[str]:
 
 
 def dependents_graph() -> dict:
-    """
-    Construct a mapping of package -> dependents, such that we can
-    run tests on all dependents of a package when a change is made.
+    """Construct a mapping of package -> dependents
+
+    Done such that we can run tests on all dependents of a package when a change is made.
     """
     dependents = defaultdict(set)
 
diff --git a/.github/scripts/check_prerelease_dependencies.py b/.github/scripts/check_prerelease_dependencies.py
index 20fcad5a97f..f445ede08fd 100644
--- a/.github/scripts/check_prerelease_dependencies.py
+++ b/.github/scripts/check_prerelease_dependencies.py
@@ -1,3 +1,5 @@
+"""Check that no dependencies allow prereleases unless we're releasing a prerelease."""
+
 import sys
 
 import tomllib
@@ -6,15 +8,14 @@ if __name__ == "__main__":
     # Get the TOML file path from the command line argument
     toml_file = sys.argv[1]
 
-    # read toml file
     with open(toml_file, "rb") as file:
         toml_data = tomllib.load(file)
 
-    # see if we're releasing an rc
+    # See if we're releasing an rc or dev version
     version = toml_data["project"]["version"]
     releasing_rc = "rc" in version or "dev" in version
 
-    # if not, iterate through dependencies and make sure none allow prereleases
+    # If not, iterate through dependencies and make sure none allow prereleases
     if not releasing_rc:
         dependencies = toml_data["project"]["dependencies"]
         for dep_version in dependencies:
diff --git a/.github/scripts/get_min_versions.py b/.github/scripts/get_min_versions.py
index 91212625b8b..c5c5ecc5704 100644
--- a/.github/scripts/get_min_versions.py
+++ b/.github/scripts/get_min_versions.py
@@ -1,3 +1,5 @@
+"""Get minimum versions of dependencies from a pyproject.toml file."""
+
 import sys
 from collections import defaultdict
 from typing import Optional
@@ -5,7 +7,7 @@ from typing import Optional
 if sys.version_info >= (3, 11):
     import tomllib
 else:
-    # for python 3.10 and below, which doesnt have stdlib tomllib
+    # For Python 3.10 and below, which doesnt have stdlib tomllib
     import tomli as tomllib
 
 import re
@@ -34,14 +36,13 @@ SKIP_IF_PULL_REQUEST = [
 
 
 def get_pypi_versions(package_name: str) -> List[str]:
-    """
-    Fetch all available versions for a package from PyPI.
+    """Fetch all available versions for a package from PyPI.
 
     Args:
-        package_name (str): Name of the package
+        package_name: Name of the package
 
     Returns:
-        List[str]: List of all available versions
+        List of all available versions
 
     Raises:
         requests.exceptions.RequestException: If PyPI API request fails
@@ -54,24 +55,23 @@ def get_pypi_versions(package_name: str) -> List[str]:
 
 
 def get_minimum_version(package_name: str, spec_string: str) -> Optional[str]:
-    """
-    Find the minimum published version that satisfies the given constraints.
+    """Find the minimum published version that satisfies the given constraints.
 
     Args:
-        package_name (str): Name of the package
-        spec_string (str): Version specification string (e.g., ">=0.2.43,<0.4.0,!=0.3.0")
+        package_name: Name of the package
+        spec_string: Version specification string (e.g., ">=0.2.43,<0.4.0,!=0.3.0")
 
     Returns:
-        Optional[str]: Minimum compatible version or None if no compatible version found
+        Minimum compatible version or None if no compatible version found
     """
-    # rewrite occurrences of ^0.0.z to 0.0.z (can be anywhere in constraint string)
+    # Rewrite occurrences of ^0.0.z to 0.0.z (can be anywhere in constraint string)
     spec_string = re.sub(r"\^0\.0\.(\d+)", r"0.0.\1", spec_string)
-    # rewrite occurrences of ^0.y.z to >=0.y.z,<0.y+1 (can be anywhere in constraint string)
+    # Rewrite occurrences of ^0.y.z to >=0.y.z,<0.y+1 (can be anywhere in constraint string)
     for y in range(1, 10):
         spec_string = re.sub(
             rf"\^0\.{y}\.(\d+)", rf">=0.{y}.\1,<0.{y + 1}", spec_string
         )
-    # rewrite occurrences of ^x.y.z to >=x.y.z,<x+1.0.0 (can be anywhere in constraint string)
+    # Rewrite occurrences of ^x.y.z to >=x.y.z,<x+1.0.0 (can be anywhere in constraint string)
     for x in range(1, 10):
         spec_string = re.sub(
             rf"\^{x}\.(\d+)\.(\d+)", rf">={x}.\1.\2,<{x + 1}", spec_string
@@ -154,22 +154,25 @@ def get_min_version_from_toml(
 
 
 def check_python_version(version_string, constraint_string):
-    """
-    Check if the given Python version matches the given constraints.
+    """Check if the given Python version matches the given constraints.
 
-    :param version_string: A string representing the Python version (e.g. "3.8.5").
-    :param constraint_string: A string representing the package's Python version constraints (e.g. ">=3.6, <4.0").
-    :return: True if the version matches the constraints, False otherwise.
+    Args:
+        version_string: A string representing the Python version (e.g. "3.8.5").
+        constraint_string: A string representing the package's Python version
+            constraints (e.g. ">=3.6, <4.0").
+
+    Returns:
+        True if the version matches the constraints
     """
 
-    # rewrite occurrences of ^0.0.z to 0.0.z (can be anywhere in constraint string)
+    # Rewrite occurrences of ^0.0.z to 0.0.z (can be anywhere in constraint string)
     constraint_string = re.sub(r"\^0\.0\.(\d+)", r"0.0.\1", constraint_string)
-    # rewrite occurrences of ^0.y.z to >=0.y.z,<0.y+1.0 (can be anywhere in constraint string)
+    # Rewrite occurrences of ^0.y.z to >=0.y.z,<0.y+1.0 (can be anywhere in constraint string)
     for y in range(1, 10):
         constraint_string = re.sub(
             rf"\^0\.{y}\.(\d+)", rf">=0.{y}.\1,<0.{y + 1}.0", constraint_string
         )
-    # rewrite occurrences of ^x.y.z to >=x.y.z,<x+1.0.0 (can be anywhere in constraint string)
+    # Rewrite occurrences of ^x.y.z to >=x.y.z,<x+1.0.0 (can be anywhere in constraint string)
     for x in range(1, 10):
         constraint_string = re.sub(
             rf"\^{x}\.0\.(\d+)", rf">={x}.0.\1,<{x + 1}.0.0", constraint_string
diff --git a/.github/scripts/prep_api_docs_build.py b/.github/scripts/prep_api_docs_build.py
index 4dad98f53c5..460a24d1fcf 100644
--- a/.github/scripts/prep_api_docs_build.py
+++ b/.github/scripts/prep_api_docs_build.py
@@ -1,5 +1,5 @@
 #!/usr/bin/env python
-"""Script to sync libraries from various repositories into the main langchain repository."""
+"""Sync libraries from various repositories into this monorepo."""
 
 import os
 import shutil
diff --git a/.github/workflows/_compile_integration_test.yml b/.github/workflows/_compile_integration_test.yml
index 4e4a1ac3bac..dc49c03da7c 100644
--- a/.github/workflows/_compile_integration_test.yml
+++ b/.github/workflows/_compile_integration_test.yml
@@ -1,3 +1,11 @@
+# Validates that a package's integration tests compile without syntax or import errors.
+#
+# (If an integration test fails to compile, it won't run.)
+#
+# Called as part of check_diffs.yml workflow
+#
+# Runs pytest with compile marker to check syntax/imports.
+
 name: '🔗 Compile Integration Tests'
 
 on:
diff --git a/.github/workflows/_integration_test.yml b/.github/workflows/_integration_test.yml
index 0579c2e7300..6af79b9421a 100644
--- a/.github/workflows/_integration_test.yml
+++ b/.github/workflows/_integration_test.yml
@@ -1,3 +1,10 @@
+
+# Runs `make integration_tests` on the specified package.
+#
+# Manually triggered via workflow_dispatch for testing with real APIs.
+#
+# Installs integration test dependencies and executes full test suite.
+
 name: '🚀 Integration Tests'
 run-name: 'Test ${{ inputs.working-directory }} on Python ${{ inputs.python-version }}'
 
@@ -83,7 +90,7 @@ jobs:
         run: |
           make integration_tests
 
-      - name: Ensure the tests did not create any additional files
+      - name: 'Ensure testing did not create/modify files'
         shell: bash
         run: |
           set -eu
diff --git a/.github/workflows/_lint.yml b/.github/workflows/_lint.yml
index 817e15de856..04af83f802a 100644
--- a/.github/workflows/_lint.yml
+++ b/.github/workflows/_lint.yml
@@ -1,6 +1,11 @@
-name: '🧹 Code Linting'
-# Runs code quality checks using ruff, mypy, and other linting tools
-# Checks both package code and test code for consistency
+# Runs linting.
+#
+# Uses the package's Makefile to run the checks, specifically the
+# `lint_package` and `lint_tests` targets.
+#
+# Called as part of check_diffs.yml workflow.
+
+name: '🧹 Linting'
 
 on:
   workflow_call:
@@ -43,14 +48,6 @@ jobs:
           working-directory: ${{ inputs.working-directory }}
 
       - name: '📦 Install Lint & Typing Dependencies'
-        # Also installs dev/lint/test/typing dependencies, to ensure we have
-        # type hints for as many of our libraries as possible.
-        # This helps catch errors that require dependencies to be spotted, for example:
-        # https://github.com/langchain-ai/langchain/pull/10249/files#diff-935185cd488d015f026dcd9e19616ff62863e8cde8c0bee70318d3ccbca98341
-        #
-        # If you change this configuration, make sure to change the `cache-key`
-        # in the `poetry_setup` action above to stop using the old cache.
-        # It doesn't matter how you change it, any change will cause a cache-bust.
         working-directory: ${{ inputs.working-directory }}
         run: |
           uv sync --group lint --group typing
@@ -60,20 +57,13 @@ jobs:
         run: |
           make lint_package
 
-      - name: '📦 Install Unit Test Dependencies'
-        # Also installs dev/lint/test/typing dependencies, to ensure we have
-        # type hints for as many of our libraries as possible.
-        # This helps catch errors that require dependencies to be spotted, for example:
-        # https://github.com/langchain-ai/langchain/pull/10249/files#diff-935185cd488d015f026dcd9e19616ff62863e8cde8c0bee70318d3ccbca98341
-        #
-        # If you change this configuration, make sure to change the `cache-key`
-        # in the `poetry_setup` action above to stop using the old cache.
-        # It doesn't matter how you change it, any change will cause a cache-bust.
+      - name: '📦 Install Test Dependencies (non-partners)'
+        # (For directories NOT starting with libs/partners/)
         if: ${{ ! startsWith(inputs.working-directory, 'libs/partners/') }}
         working-directory: ${{ inputs.working-directory }}
         run: |
           uv sync --inexact --group test
-      - name: '📦 Install Unit + Integration Test Dependencies'
+      - name: '📦 Install Test Dependencies'
         if: ${{ startsWith(inputs.working-directory, 'libs/partners/') }}
         working-directory: ${{ inputs.working-directory }}
         run: |
diff --git a/.github/workflows/_release.yml b/.github/workflows/_release.yml
index 8b1e272bdc1..4e0adfc6033 100644
--- a/.github/workflows/_release.yml
+++ b/.github/workflows/_release.yml
@@ -1,3 +1,9 @@
+# Builds and publishes LangChain packages to PyPI.
+#
+# Manually triggered, though can be used as a reusable workflow (workflow_call).
+#
+# Handles version bumping, building, and publishing to PyPI with authentication.
+
 name: '🚀 Package Release'
 run-name: 'Release ${{ inputs.working-directory }} ${{ inputs.release-version }}'
 on:
@@ -52,8 +58,8 @@ jobs:
 
       # We want to keep this build stage *separate* from the release stage,
       # so that there's no sharing of permissions between them.
-      # The release stage has trusted publishing and GitHub repo contents write access,
-      # and we want to keep the scope of that access limited just to the release job.
+      # (Release stage has trusted publishing and GitHub repo contents write access,
+      #
       # Otherwise, a malicious `build` step (e.g. via a compromised dependency)
       # could get access to our GitHub or PyPI credentials.
       #
@@ -293,11 +299,14 @@ jobs:
         working-directory: ${{ inputs.working-directory }}
 
       - name: Check for prerelease versions
+        # Block release if any dependencies allow prerelease versions
+        # (unless this is itself a prerelease version)
         working-directory: ${{ inputs.working-directory }}
         run: |
           uv run python $GITHUB_WORKSPACE/.github/scripts/check_prerelease_dependencies.py pyproject.toml
 
       - name: Get minimum versions
+        # Find the minimum published versions that satisfies the given constraints
         working-directory: ${{ inputs.working-directory }}
         id: min-version
         run: |
@@ -322,6 +331,7 @@ jobs:
         working-directory: ${{ inputs.working-directory }}
 
       - name: Run integration tests
+        # Uses the Makefile's `integration_tests` target for the specified package
         if: ${{ startsWith(inputs.working-directory, 'libs/partners/') }}
         env:
           AI21_API_KEY: ${{ secrets.AI21_API_KEY }}
@@ -362,7 +372,10 @@ jobs:
         working-directory: ${{ inputs.working-directory }}
 
   # Test select published packages against new core
+  # Done when code changes are made to langchain-core
   test-prior-published-packages-against-new-core:
+    # Installs the new core with old partners: Installs the new unreleased core
+    # alongside the previously published partner packages and runs integration tests
     needs:
       - build
       - release-notes
@@ -390,6 +403,7 @@ jobs:
 
       # We implement this conditional as Github Actions does not have good support
       # for conditionally needing steps. https://github.com/actions/runner/issues/491
+      # TODO: this seems to be resolved upstream, so we can probably remove this workaround
       - name: Check if libs/core
         run: |
           if [ "${{ startsWith(inputs.working-directory, 'libs/core') }}" != "true" ]; then
@@ -444,6 +458,7 @@ jobs:
           make integration_tests
 
   publish:
+    # Publishes the package to PyPI
     needs:
       - build
       - release-notes
@@ -486,6 +501,7 @@ jobs:
           attestations: false
 
   mark-release:
+    # Marks the GitHub release with the new version tag
     needs:
       - build
       - release-notes
@@ -495,7 +511,7 @@ jobs:
     runs-on: ubuntu-latest
     permissions:
       # This permission is needed by `ncipollo/release-action` to
-      # create the GitHub release.
+      # create the GitHub release/tag
       contents: write
 
     defaults:
diff --git a/.github/workflows/_test.yml b/.github/workflows/_test.yml
index b49cb5440bd..488b0d65b2d 100644
--- a/.github/workflows/_test.yml
+++ b/.github/workflows/_test.yml
@@ -1,6 +1,7 @@
-name: '🧪 Unit Testing'
 # Runs unit tests with both current and minimum supported dependency versions
-# to ensure compatibility across the supported range
+# to ensure compatibility across the supported range.
+
+name: '🧪 Unit Testing'
 
 on:
   workflow_call:
diff --git a/.github/workflows/_test_doc_imports.yml b/.github/workflows/_test_doc_imports.yml
index 5347c4d7c47..dc2c55fbd73 100644
--- a/.github/workflows/_test_doc_imports.yml
+++ b/.github/workflows/_test_doc_imports.yml
@@ -1,3 +1,10 @@
+# Validates that all import statements in `.ipynb` notebooks are correct and functional.
+#
+# Called as part of check_diffs.yml.
+#
+# Installs test dependencies and LangChain packages in editable mode and
+# runs check_imports.py.
+
 name: '📑 Documentation Import Testing'
 
 on:
diff --git a/.github/workflows/_test_pydantic.yml b/.github/workflows/_test_pydantic.yml
index 89e4f0dae11..7363231fd62 100644
--- a/.github/workflows/_test_pydantic.yml
+++ b/.github/workflows/_test_pydantic.yml
@@ -1,3 +1,5 @@
+# Facilitate unit testing against different Pydantic versions for a provided package.
+
 name: '🐍 Pydantic Version Testing'
 
 on:
diff --git a/.github/workflows/api_doc_build.yml b/.github/workflows/api_doc_build.yml
index 0702dc57c6e..f7c2c62792b 100644
--- a/.github/workflows/api_doc_build.yml
+++ b/.github/workflows/api_doc_build.yml
@@ -1,11 +1,14 @@
+# Build the API reference documentation.
+#
+# Runs daily. Can also be triggered manually for immediate updates.
+
 name: '📚 API Docs'
 run-name: 'Build & Deploy API Reference'
-# Runs daily or can be triggered manually for immediate updates
 
 on:
   workflow_dispatch:
   schedule:
-    - cron:  '0 13 * * *'  # Daily at 1PM UTC
+    - cron:  '0 13 * * *'  # Runs daily at 1PM UTC (9AM EDT/6AM PDT)
 env:
   PYTHON_VERSION: "3.11"
 
diff --git a/.github/workflows/check-broken-links.yml b/.github/workflows/check-broken-links.yml
index 6c949b5bbf8..4f1f0a1ce20 100644
--- a/.github/workflows/check-broken-links.yml
+++ b/.github/workflows/check-broken-links.yml
@@ -1,9 +1,11 @@
+# Runs broken link checker in /docs on a daily schedule.
+
 name: '🔗 Check Broken Links'
 
 on:
   workflow_dispatch:
   schedule:
-    - cron:  '0 13 * * *'
+    - cron:  '0 13 * * *'  # Runs daily at 1PM UTC (9AM EDT/6AM PDT)
 
 permissions:
   contents: read
diff --git a/.github/workflows/check_core_versions.yml b/.github/workflows/check_core_versions.yml
index 7905bf06ce3..0c0122d435d 100644
--- a/.github/workflows/check_core_versions.yml
+++ b/.github/workflows/check_core_versions.yml
@@ -1,6 +1,8 @@
+# Ensures version numbers in pyproject.toml and version.py stay in sync.
+#
+# (Prevents releases with mismatched version numbers)
+
 name: '🔍 Check `core` Version Equality'
-# Ensures version numbers in pyproject.toml and version.py stay in sync
-# Prevents releases with mismatched version numbers
 
 on:
   pull_request:
diff --git a/.github/workflows/check_diffs.yml b/.github/workflows/check_diffs.yml
index 37eabe5583d..0fb19943183 100644
--- a/.github/workflows/check_diffs.yml
+++ b/.github/workflows/check_diffs.yml
@@ -1,3 +1,18 @@
+# Primary CI workflow.
+#
+# Only runs against packages that have changed files.
+#
+# Runs:
+# - Linting (_lint.yml)
+# - Unit Tests (_test.yml)
+# - Pydantic compatibility tests (_test_pydantic.yml)
+# - Documentation import tests (_test_doc_imports.yml)
+# - Integration test compilation checks (_compile_integration_test.yml)
+# - Extended test suites that require additional dependencies
+# - Codspeed benchmarks (if not labeled 'codspeed-ignore')
+#
+# Reports status to GitHub checks and PR status.
+
 name: '🔧 CI'
 
 on:
@@ -11,8 +26,8 @@ on:
 # cancel the earlier run in favor of the next run.
 #
 # There's no point in testing an outdated version of the code. GitHub only allows
-# a limited number of job runners to be active at the same time, so it's better to cancel
-# pointless jobs early so that more useful jobs can run sooner.
+# a limited number of job runners to be active at the same time, so it's better to
+# cancel pointless jobs early so that more useful jobs can run sooner.
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
diff --git a/.github/workflows/check_new_docs.yml b/.github/workflows/check_new_docs.yml
index cf988ba1153..f026a765b06 100644
--- a/.github/workflows/check_new_docs.yml
+++ b/.github/workflows/check_new_docs.yml
@@ -1,3 +1,6 @@
+# For integrations, we run check_templates.py to ensure that new docs use the correct
+# templates based on their type. See the script for more details.
+
 name: '📑 Integration Docs Lint'
 
 on:
diff --git a/.github/workflows/people.yml b/.github/workflows/people.yml
index 3347d61ff5e..0d4b1b80909 100644
--- a/.github/workflows/people.yml
+++ b/.github/workflows/people.yml
@@ -1,9 +1,11 @@
+# Updates the LangChain People data by fetching the latest info from the LangChain Git.
+# TODO: broken/not used
+
 name: '👥 LangChain People'
 run-name: 'Update People Data'
-# This workflow updates the LangChain People data by fetching the latest information from the LangChain Git
 on:
   schedule:
-    - cron: "0 14 1 * *"
+    - cron: "0 14 1 * *"  # Runs at 14:00 UTC on the 1st of every month (10AM EDT/7AM PDT)
   push:
     branches: [jacob/people]
   workflow_dispatch:
diff --git a/.github/workflows/labeler.yml b/.github/workflows/pr_labeler_file.yml
similarity index 71%
rename from .github/workflows/labeler.yml
rename to .github/workflows/pr_labeler_file.yml
index 6e4d60a0374..503f657750f 100644
--- a/.github/workflows/labeler.yml
+++ b/.github/workflows/pr_labeler_file.yml
@@ -1,3 +1,7 @@
+# Label PRs based on changed files.
+#
+# See `.github/pr-file-labeler.yml` to see rules for each label/directory.
+
 name: "🏷️ Pull Request Labeler"
 
 on:
@@ -18,5 +22,5 @@ jobs:
       uses: actions/labeler@v6
       with:
         repo-token: "${{ secrets.GITHUB_TOKEN }}"
-        configuration-path: .github/labeler.yml
+        configuration-path: .github/pr-file-labeler.yml
         sync-labels: false
diff --git a/.github/workflows/pr_title_labeler.yml b/.github/workflows/pr_labeler_title.yml
similarity index 79%
rename from .github/workflows/pr_title_labeler.yml
rename to .github/workflows/pr_labeler_title.yml
index d5aa8e6c7b9..43f0547cbee 100644
--- a/.github/workflows/pr_title_labeler.yml
+++ b/.github/workflows/pr_labeler_title.yml
@@ -1,3 +1,7 @@
+# Label PRs based on their titles.
+#
+# See `.github/pr-title-labeler.yml` to see rules for each label/title pattern.
+
 name: "🏷️ PR Title Labeler"
 
 on:
diff --git a/.github/workflows/pr_lint.yml b/.github/workflows/pr_lint.yml
index 1adca680420..56634082a5f 100644
--- a/.github/workflows/pr_lint.yml
+++ b/.github/workflows/pr_lint.yml
@@ -1,29 +1,30 @@
-# -----------------------------------------------------------------------------
-# PR Title Lint Workflow
+# PR title linting.
 #
-# Purpose:
-#   Enforces Conventional Commits format for pull request titles to maintain a
-#   clear, consistent, and machine-readable change history across our repository.
-#   This helps with automated changelog generation and semantic versioning.
+# FORMAT (Conventional Commits 1.0.0):
 #
-# Enforced Commit Message Format (Conventional Commits 1.0.0):
 #   <type>[optional scope]: <description>
 #   [optional body]
 #   [optional footer(s)]
 #
+# Examples:
+#     feat(core): add multi‐tenant support
+#     fix(cli): resolve flag parsing error
+#     docs: update API usage examples
+#     docs(openai): update API usage examples
+#
 # Allowed Types:
-#   • feat       — a new feature (MINOR bump)
-#   • fix        — a bug fix (PATCH bump)
-#   • docs       — documentation only changes
-#   • style      — formatting, missing semi-colons, etc.; no code change
-#   • refactor   — code change that neither fixes a bug nor adds a feature
-#   • perf       — code change that improves performance
-#   • test       — adding missing tests or correcting existing tests
-#   • build      — changes that affect the build system or external dependencies
-#   • ci         — continuous integration/configuration changes
-#   • chore      — other changes that don't modify src or test files
-#   • revert     — reverts a previous commit
-#   • release    — prepare a new release
+#   * feat       — a new feature (MINOR)
+#   * fix        — a bug fix (PATCH)
+#   * docs       — documentation only changes (either in /docs or code comments)
+#   * style      — formatting, linting, etc.; no code change or typing refactors
+#   * refactor   — code change that neither fixes a bug nor adds a feature
+#   * perf       — code change that improves performance
+#   * test       — adding tests or correcting existing
+#   * build      — changes that affect the build system/external dependencies
+#   * ci         — continuous integration/configuration changes
+#   * chore      — other changes that don't modify source or test files
+#   * revert     — reverts a previous commit
+#   * release    — prepare a new release
 #
 # Allowed Scopes (optional):
 #   core, cli, langchain, langchain_v1, langchain_legacy, standard-tests,
@@ -31,21 +32,12 @@
 #   huggingface, mistralai, nomic, ollama, openai, perplexity, prompty, qdrant,
 #   xai, infra
 #
-# Rules & Tips for New Committers:
-#   1. Subject (type) must start with a lowercase letter and, if possible, be
-#      followed by a scope wrapped in parenthesis `(scope)`
-#   2. Breaking changes:
-#        – Append "!" after type/scope (e.g., feat!: drop Node 12 support)
-#        – Or include a footer "BREAKING CHANGE: <details>"
-#   3. Example PR titles:
-#        feat(core): add multi‐tenant support
-#        fix(cli): resolve flag parsing error
-#        docs: update API usage examples
-#        docs(openai): update API usage examples
+# Rules:
+#   1. The 'Type' must start with a lowercase letter.
+#   2. Breaking changes: append "!" after type/scope (e.g., feat!: drop x support)
 #
-# Resources:
-#   • Conventional Commits spec: https://www.conventionalcommits.org/en/v1.0.0/
-# -----------------------------------------------------------------------------
+# Enforces Conventional Commits format for pull request titles to maintain a clear and
+# machine-readable change history.
 
 name: '🏷️ PR Title Lint'
 
@@ -57,7 +49,7 @@ on:
     types: [opened, edited, synchronize]
 
 jobs:
-  # Validates that PR title follows Conventional Commits specification
+  # Validates that PR title follows Conventional Commits 1.0.0 specification
   lint-pr-title:
     name: 'validate format'
     runs-on: ubuntu-latest
diff --git a/.github/workflows/run_notebooks.yml b/.github/workflows/run_notebooks.yml
index 5649d37e6f7..3f3971658db 100644
--- a/.github/workflows/run_notebooks.yml
+++ b/.github/workflows/run_notebooks.yml
@@ -1,3 +1,5 @@
+# Integration tests for documentation notebooks.
+
 name: '📓 Validate Documentation Notebooks'
 run-name: 'Test notebooks in ${{ inputs.working-directory  }}'
 on:
diff --git a/.github/workflows/scheduled_test.yml b/.github/workflows/scheduled_test.yml
index f5266b5d879..3c6e40d8325 100644
--- a/.github/workflows/scheduled_test.yml
+++ b/.github/workflows/scheduled_test.yml
@@ -1,8 +1,14 @@
+# Routine integration tests against partner libraries with live API credentials.
+#
+# Uses `make integration_tests` for each library in the matrix.
+#
+# Runs daily. Can also be triggered manually for immediate updates.
+
 name: '⏰ Scheduled Integration Tests'
 run-name: "Run Integration Tests - ${{ inputs.working-directory-force || 'all libs' }} (Python ${{ inputs.python-version-force || '3.9, 3.11' }})"
 
 on:
-  workflow_dispatch:  # Allows maintainers to trigger the workflow manually in GitHub UI
+  workflow_dispatch:
     inputs:
       working-directory-force:
         type: string
@@ -54,7 +60,7 @@ jobs:
           echo $matrix
           echo "matrix=$matrix" >> $GITHUB_OUTPUT
   # Run integration tests against partner libraries with live API credentials
-  # Tests are run with both Poetry and UV depending on the library's setup
+  # Tests are run with Poetry or UV depending on the library's setup
   build:
     if: github.repository_owner == 'langchain-ai' || github.event_name != 'schedule'
     name: '🐍 Python ${{ matrix.python-version }}: ${{ matrix.working-directory }}'
diff --git a/docs/scripts/check_imports.py b/docs/scripts/check_imports.py
index 461d2bb858f..aabe1a1f0ab 100644
--- a/docs/scripts/check_imports.py
+++ b/docs/scripts/check_imports.py
@@ -1,4 +1,20 @@
-"""This script checks documentation for broken import statements."""
+"""Check documentation for broken import statements.
+
+Validates that all import statements in Jupyter notebooks within the documentation
+directory are functional and can be successfully imported.
+
+- Scans all `.ipynb` files in `docs/`
+- Extracts import statements from code cells
+- Tests each import to ensure it works
+- Reports any broken imports that would fail for users
+
+Usage:
+    python docs/scripts/check_imports.py
+
+Exit codes:
+    0: All imports are valid
+    1: Found broken imports (ImportError raised)
+"""
 
 import importlib
 import json