[備忘録] Gradio MCPサーバーを試してみたら、docstringの重要性に気づいた話 #Python – Qiita

description, parameters = utils.get_function_description(block_fn.fn)

def get_function_description(fn: Callable) -> tuple[str, dict[str, str]]:
    """
    Get the description of a function and its parameters by parsing the docstring.
    ...
    """
    fn_docstring = fn.__doc__
    description = ""
    parameters = {}

    if not fn_docstring:
        return description, parameters

    lines = fn_docstring.strip().split("\n")

    # 説明部分の抽出
    description_lines = []
    for line in lines:
        line = line.strip()
        if line.startswith(("Args:", "Parameters:", "Arguments:")):
            break
        if line:
            description_lines.append(line)

    description = " ".join(description_lines)

    # パラメータ部分の抽出
    try:
        param_start_idx = next(
            (
                i
                for i, line in enumerate(lines)
                if line.strip().startswith(("Args:", "Parameters:", "Arguments:"))
            ),
            len(lines),
        )

        for line in lines[param_start_idx + 1 :]:
            line = line.strip()
            if not line:
                continue

            try:
                if ":" in line:
                    param_name, param_desc = line.split(":", 1)
                    param_name = param_name.split(" ")[0].strip()
                    if param_name:
                        parameters[param_name] = param_desc.strip()
            except Exception:
                continue

    except Exception:
        pass

    return description, parameters