docs: add Google-style docstrings to tools and llms modules (zapier, … (#31957)
**Description:**
Added standardized Google-style docstrings to improve documentation
consistency across key modules.
Updated files:
- `tools/zapier/tool.py`
- `tools/jira/tool.py`
- `tools/json/tool.py`
- `llms/base.py`
These changes enhance readability and maintain consistency with
LangChain’s documentation style guide.
**Issue:**
Fixes #21983
**Dependencies:**
None
**Twitter handle :**
@Akshara_p_