langchain/agents/conversational_chat/base.py/ConversationalChatAgent/_construct_scratchpad
class ConversationalChatAgent:    def _construct_scratchpad(
        self, intermediate_steps: List[Tuple[AgentAction, str]]
    ) -> List[BaseMessage]:
        """Construct the scratchpad that lets the agent continue its thought process."""
        thoughts: List[BaseMessage] = []
        for action, observation in intermediate_steps:
            thoughts.append(AIMessage(content=action.log))
            human_message = HumanMessage(
                content=self.template_tool_response.format(observation=observation)
            )
            thoughts.append(human_message)
        return thoughts