refactor: narrow except clause and extract validation error helper

Author: yuvrajangadsingh

src/google/adk/flows/llm_flows/functions.py

@@ -149,14 +149,7 @@ def run_sync_tool():
       if isinstance(tool, FunctionTool):
         args_to_call, validation_errors = tool._preprocess_args(args)
         if validation_errors:
-          validation_errors_str = '\n'.join(validation_errors)
-          return {
-              'error': (
-                  f'Invoking `{tool.name}()` failed due to argument'
-                  f' validation errors:\n{validation_errors_str}\nYou could'
-                  ' retry calling this tool with corrected argument types.'
-              )
-          }
+          return tool._build_validation_error_response(validation_errors)
         signature = inspect.signature(tool.func)
         valid_params = {param for param in signature.parameters}
         if tool._context_param_name in valid_params:

src/google/adk/tools/crewai_tool.py

@@ -78,11 +78,7 @@ async def run_async(
     args_to_call, validation_errors = self._preprocess_args(args)
 
     if validation_errors:
-      validation_errors_str = '\n'.join(validation_errors)
-      error_str = f"""Invoking `{self.name}()` failed due to argument validation errors:
-{validation_errors_str}
-You could retry calling this tool with corrected argument types."""
-      return {'error': error_str}
+      return self._build_validation_error_response(validation_errors)
 
     signature = inspect.signature(self.func)
     valid_params = {param for param in signature.parameters}

src/google/adk/tools/function_tool.py

@@ -173,13 +173,26 @@ def _preprocess_args(
             f"Parameter '{param_name}': expected type '{target_type}',"
             f' validation error: {e}'
         )
-      except Exception:
+      except (TypeError, NameError):
         # TypeAdapter could not handle this annotation (e.g. a forward
         # reference string). Skip validation silently.
         pass
 
     return converted_args, validation_errors
 
+  def _build_validation_error_response(
+      self, validation_errors: list[str]
+  ) -> dict[str, str]:
+    """Formats validation errors into an error dict for the LLM."""
+    validation_errors_str = '\n'.join(validation_errors)
+    return {
+        'error': (
+            f'Invoking `{self.name}()` failed due to argument validation'
+            f' errors:\n{validation_errors_str}\nYou could retry calling'
+            ' this tool with corrected argument types.'
+        )
+    }
+
   @override
   async def run_async(
       self, *, args: dict[str, Any], tool_context: ToolContext
@@ -190,11 +203,7 @@ async def run_async(
     args_to_call, validation_errors = self._preprocess_args(args)
 
     if validation_errors:
-      validation_errors_str = '\n'.join(validation_errors)
-      error_str = f"""Invoking `{self.name}()` failed due to argument validation errors:
-{validation_errors_str}
-You could retry calling this tool with corrected argument types."""
-      return {'error': error_str}
+      return self._build_validation_error_response(validation_errors)
 
     signature = inspect.signature(self.func)
     valid_params = {param for param in signature.parameters}