A shared-catalogue address you named does not answer

It concerns UCP, the shared catalogue standard. The Universal Commerce Protocol. A shared format Google and Shopify use so an agent can read your catalogue and build a basket without scraping your pages.

Agents can usually carry on, but more slowly or less sure of what they found, and an unsure agent is likelier to recommend another store.

Every endpoint the manifest advertises must resolve. An agent plans around what the manifest promises, so a declared capability that is not there costs more than an undeclared one. An endpoint answering 401 or 403 is fine — that is authentication, not absence.

Run the check that reported UCP_CAPABILITY_UNSUPPORTED again after the change. The scan needs no account; an issue found during an AI shopping test needs that test run again.

$ npx @tragent/cli scan https://your-store.com

• The shared-catalogue test suite found a failure
• Your shared-catalogue profile does not match the standard