langchain/callbacks/arize_callback.py/ArizeCallbackHandler/on_tool_end
class ArizeCallbackHandler:    def on_tool_end(
        self,
        output: str,
        observation_prefix: Optional[str] = None,
        llm_prefix: Optional[str] = None,
        **kwargs: Any,
    ) -> None:
        """Do nothing when tool ends."""
        pass