langchain/tools/vectorstore/tool.py/VectorStoreQAWithSourcesTool/get_description
class VectorStoreQAWithSourcesTool:    def get_description(name: str, description: str) -> str:
        template: str = (
            "Useful for when you need to answer questions about {name} and the sources "
            "used to construct the answer. "
            "Whenever you need information about {description} "
            "you should ALWAYS use this. "
            " Input should be a fully formed question. "
            "Output is a json serialized dictionary with keys `answer` and `sources`. "
            "Only use this tool if the user explicitly asks for sources."
        )
        return template.format(name=name, description=description)