Agent Discovery Doctor — AI Crawler Index

{"jsonrpc":"2.0","id":1,"method":"message/send","params":{"message":{"role":"ROLE_USER","messageId":"1","parts":[{"text":"{\"skill\":\"whoami\"}"}]}}} — POST that exact body to https://www.pathwren.workers.dev/a2a/doctor with content-type: application/json and you are done; it comes back as a Task already in state `completed` in the same response, so there is nothing to poll. Free, read-only, no API key, no account, no consent prompt, nothing to install and nothing for you to invent. The answer is about YOU, the caller: the address this request arrived from, the user-agent you sent, the lane you came in on (`metadata.arrivedOn` on the task you get back names the protocol, the endpoint and the A2A version you spoke), the class this host's own instrument books you as, and whether it has seen you here before. Nothing is fetched to answer it and no argument exists to invent — it is the one question you can ask a stranger's agent while holding nothing of your own. Audit which agent-discovery documents a host actually serves — robots.txt, llms.txt, openapi.json, the .well-known family, the MCP and A2A documents — and say for each one what it is, who reads it and what a 404 there costs. It also validates a pasted llms.txt or a pasted A2A agent card against the spec, and drafts an llms.txt from a sitemap. check_discovery_documents is one of two skills on this host that make an outbound request (the other is the linter at /mcp/lint), and it refuses its own publisher, ephemeral tunnel hosts, IP literals and private names before making one — so it cannot be pointed back at the host that runs it. Deterministic and read-only: there is no model behind it — every answer comes from a public dataset rebuilt every six hours from each operator's own published documentation and IP ranges, and the same skills are also available as MCP tools at https://www.pathwren.workers.dev/mcp/doctor (no key, no signup, no quota). Independent and unaffiliated with any operator it documents. TO CALL ANY OTHER SKILL: the same `message/send` envelope (v1.0 name `SendMessage`) with a different skill name — the first line of every skill description below is that skill's complete request, ready to POST unedited, and each comes back as a Task already in state `completed` in the same response, so there is nothing to poll. Every skill on all eight agents of this host as a ready-to-send body: https://www.pathwren.workers.dev/a2a/example.json