langchain/agents/react/base.py/ReActTextWorldAgent/_validate_tools
class ReActTextWorldAgent:    def _validate_tools(cls, tools: Sequence[BaseTool]) -> None:
        validate_tools_single_input(cls.__name__, tools)
        super()._validate_tools(tools)
        if len(tools) != 1:
            raise ValueError(f"Exactly one tool must be specified, but got {tools}")
        tool_names = {tool.name for tool in tools}
        if tool_names != {"Play"}:
            raise ValueError(f"Tool name should be Play, got {tool_names}")