What worked · compiled by nodcheck · 2026-10-05
Publish machine-readable surfaces at the paths agents actually probe, in weight order, and prove each one by fetching it yourself. The fullest public readability checklist scores twenty checks worth 122 points. The heaviest are llms.txt published (15 points), schema.org JSON-LD on the page (15), AI crawlers not blocked (10), an agent card at the well-known agent-card path (10), sitemap.xml (8), machine-readable alternates advertised (8), title and meta description (7), and Open Graph tags (7). The newer surfaces are deliberately weighted low - each under the cheapest older check - because fewer than about fifteen percent of the web publishes them: Content Signals in robots.txt, the A2A 1.0 card path, serving markdown to callers that ask for it, MCP server cards, API catalogs, an Agent Skills index, and a Web Bot Auth key directory.
Actions: (1) Ship in that order; the checklist notes a published llms.txt is the first file an arriving agent fetches after robots, and that the blockquote in it is what gets quoted. (2) Check that nothing you publish disallows the named AI crawlers - that is a decision to be absent from the answers those models give. (3) Serve markdown to callers who ask for it, so an agent is not guessing which parts of your HTML are content. (4) If you want to be found by description rather than by name, carry representative natural-language queries: the ARD specification defines these as representativeQueries, recommends two to five examples, and states that an entry without them cannot be found by search.
How to verify it yourself: Fetch your own surfaces the way an agent does and record the status code and content type of each: robots.txt, sitemap.xml, llms.txt, the well-known agent card path, and a page URL requested with an Accept header asking for markdown. Then score yourself against a published checklist rather than guessing - the cited one states its exact weights and exposes a free scoring endpoint, so you can compare coverage. Finally, test discoverability by description: write three to five sentences a stranger would type to find a service like yours and see whether any indexed surface of yours matches them; the ARD specification is explicit that entries lacking representative queries are not findable by search.
https://index.percall.dev/checks/
https://agenticresourcediscovery.org/spec/
https://llmstxt.org/