fix: incorrect logic in LlmRequest.append_tools and make BaseTool to call it

PiperOrigin-RevId: 792642882

Author: seanzhougoogle

src/google/adk/models/llm_request.py

@@ -24,6 +24,24 @@
 from ..tools.base_tool import BaseTool
 
 
+def _find_tool_with_function_declarations(
+ llm_request: LlmRequest,
+) -> Optional[types.Tool]:
+ """Find an existing Tool with function_declarations in the LlmRequest."""
+ # TODO: add individual tool with declaration and merge in google_llm.py
+ if not llm_request.config or not llm_request.config.tools:
+ return None
+
+ return next(
+ (
+ tool
+ for tool in llm_request.config.tools
+ if isinstance(tool, types.Tool) and tool.function_declarations
+ ),
+ None,
+ )
+
+
 class LlmRequest(BaseModel):
  """LLM request class that allows passing in tools, output schema and system
 
@@ -81,15 +99,26 @@ def append_tools(self, tools: list[BaseTool]) -> None:
  return
  declarations = []
  for tool in tools:
- if isinstance(tool, BaseTool):
- declaration = tool._get_declaration()
- else:
- declaration = tool.get_declaration()
+ declaration = tool._get_declaration()
  if declaration:
  declarations.append(declaration)
  self.tools_dict[tool.name] = tool
  if declarations:
- self.config.tools.append(types.Tool(function_declarations=declarations))
+ if self.config.tools is None:
+ self.config.tools = []
+
+ # Find existing tool with function_declarations and append to it
+ if tool_with_function_declarations := _find_tool_with_function_declarations(
+ self
+ ):
+ if tool_with_function_declarations.function_declarations is None:
+ tool_with_function_declarations.function_declarations = []
+ tool_with_function_declarations.function_declarations.extend(
+ declarations
+ )
+ else:
+ # No existing tool with function_declarations, create new one
+ self.config.tools.append(types.Tool(function_declarations=declarations))
 
  def set_output_schema(self, base_model: type[BaseModel]) -> None:
  """Sets the output schema for the request.

src/google/adk/tools/base_tool.py

@@ -125,30 +125,8 @@ async def process_llm_request(
  tool_context: The context of the tool.
  llm_request: The outgoing LLM request, mutable this method.
  """
- if (function_declaration := self._get_declaration()) is None:
- return
-
- llm_request.tools_dict[self.name] = self
- if tool_with_function_declarations := _find_tool_with_function_declarations(
- llm_request
- ):
- if tool_with_function_declarations.function_declarations is None:
- tool_with_function_declarations.function_declarations = []
- tool_with_function_declarations.function_declarations.append(
- function_declaration
- )
- else:
- llm_request.config = (
- types.GenerateContentConfig()
- if not llm_request.config
- else llm_request.config
- )
- llm_request.config.tools = (
- [] if not llm_request.config.tools else llm_request.config.tools
- )
- llm_request.config.tools.append(
- types.Tool(function_declarations=[function_declaration])
- )
+ # Use the consolidated logic in LlmRequest.append_tools
+ llm_request.append_tools([self])
 
  @property
  def _api_variant(self) -> GoogleLLMVariant:
@@ -232,20 +210,3 @@ def from_config(
  else:
  logger.warning("Unsupported parsing for argument: %s.", param_name)
  return cls(**kwargs)
-
-
-def _find_tool_with_function_declarations(
- llm_request: LlmRequest,
-) -> Optional[types.Tool]:
- # TODO: add individual tool with declaration and merge in google_llm.py
- if not llm_request.config or not llm_request.config.tools:
- return None
-
- return next(
- (
- tool
- for tool in llm_request.config.tools
- if isinstance(tool, types.Tool) and tool.function_declarations
- ),
- None,
- )