Call any research tool and get its structured payload

Every tool the MCP server offers, callable over plain HTTP: POST a JSON object of arguments (the tool's inputSchema; see GET /api/tool) and receive the handler's own dict — fields rather than Markdown. A tool-reported error comes back as HTTP 200 with an error key and _is_error true; an unknown tool is 404; invalid arguments are 422. Read-only; the same rate limits apply.