fix(core): prevent inherited docstrings for class-based tools

Author: R-Fischer47

libs/core/langchain_core/tools/base.py

@@ -192,6 +192,9 @@ def _infer_arg_descriptions(
 ) -> tuple[str | None, dict]:
     """Infer argument descriptions from function docstring and annotations."""
     annotations = typing.get_type_hints(fn, include_extras=True)
+    description: str | None
+    arg_descriptions: dict
+
     if parse_docstring:
         description, arg_descriptions = _parse_python_function_docstring(
             fn, annotations, error_on_invalid_docstring=error_on_invalid_docstring

libs/core/langchain_core/tools/structured.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import inspect
 import textwrap
 from collections.abc import Awaitable, Callable
 from inspect import signature
@@ -218,7 +219,9 @@ def add(a: int, b: int) -> int:
                 raise TypeError(msg)
 
         if description_ is None:
-            if is_basemodel_subclass(source_function):
+            if inspect.isclass(source_function) and is_basemodel_subclass(
+                source_function
+            ):
                 description_ = ""
             else:
                 msg = "Function must have a docstring if description not provided."