langchain/callbacks/comet_ml_callback.py/CometCallbackHandler/on_tool_end
class CometCallbackHandler:    def on_tool_end(self, output: str, **kwargs: Any) -> None:
        """Run when tool ends running."""
        self.step += 1
        self.tool_ends += 1
        self.ends += 1

        resp = self._init_resp()
        resp.update({"action": "on_tool_end"})
        resp.update(self.get_custom_callback_meta())
        if self.stream_logs:
            self._log_stream(output, resp, self.step)

        resp.update({"output": output})
        self.action_records.append(resp)