def _run(
        self,
        query: str,
        run_manager: Optional[CallbackManagerForToolRun] = None,
    ) -> str:
        """Use the tool."""
        chain = RetrievalQA.from_chain_type(
            self.llm, retriever=self.vectorstore.as_retriever()
        )
        return chain.run(query)
    async def _arun(
        self,
        query: str,
        run_manager: Optional[AsyncCallbackManagerForToolRun] = None,
    ) -> str:
        """Use the tool asynchronously."""
        raise NotImplementedError("VectorStoreQATool does not support async")
[docs]class VectorStoreQAWithSourcesTool(BaseVectorStoreTool, BaseTool):
    """Tool for the VectorDBQAWithSources chain."""
[docs]    @staticmethod
    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)
    def _run(
        self,
        query: str,
        run_manager: Optional[CallbackManagerForToolRun] = None,
    ) -> str:
        """Use the tool."""
        chain = RetrievalQAWithSourcesChain.from_chain_type(
            self.llm, retriever=self.vectorstore.as_retriever()
        )
rtdocs_stable/api.python.langchain.com/en/stable/_modules/langchain/tools/vectorstore/tool.html