Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The readOnlyHint=true annotation is consistent with the query-style description, so the description need not restate safety. It adds the shape of the result ('authorization status, brand info, authorized SKUs, and expiry'), but says nothing about what happens when a DID is unknown or unauthorized, nor about errors or rate limits.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.