The server resolves the working directory via ``os.getcwd()`` so it inherits
whatever environment the MCP process currently has.

Args:
    prompt: All instructions/context the agent needs for the task.

Returns:
    The agent's final response (clean output from Codex CLI).

Each spawned agent reuses the server's current working directory
(``os.getcwd()``).

Args:
    agents: List of agent specs, each with a 'prompt' entry.
            Example: [
                {"prompt": "Create math.md"},
                {"prompt": "Create story.md"}
            ]

Returns:
    List of results with 'index', 'output', and optional 'error' fields.