Your first check

Put an address into the checker and wait. No account, no card, no email.

The check fetches what an agent would fetch, from outside, exactly as an agent would. It follows no redirects on the UCP profile, because the specification forbids them there and an agent would not follow one either. Following it would hide the exact failure worth finding.

Reading the result

Every run answers three things: your UCP profile, your WebMCP tools, and your agent access rules (what robots.txt allows the agent crawlers to do). You get one of four outcomes per area, and the difference between them matters:

A grade. We found an integration and assessed it. See reading a report for what caps a grade.

Not implemented. Nothing was served at /.well-known/ucp, or nothing WebMCP-shaped appears in your page. This is a legitimate state, not a failure — plenty of sites have no reason to implement either standard.

Could not tell. The check did not complete: your origin rate limited us, timed out, or returned a server error. This says nothing about your integration, and we will not pretend otherwise by grading it. Try again shortly.

A blocking failure without an integration. Rare and worth acting on. It means something is actively broken — a profile that redirects, say — found before we could rule the integration in or out.

How the WebMCP result is produced

WebMCP tools are registered while your page runs, so the check loads your page in a real browser and captures exactly what an assistant would receive, alongside a read of your HTML and same-origin scripts. When the browser tier could not run, the report says so on its face and grades only what the static read can support: a strong hint rather than proof.

What a check cannot tell you

Whether it still passes tomorrow. A check is a snapshot, and the whole problem with agent readiness is that it breaks quietly between the times you think to look. That is what adding a site is for.