Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds useful behavior beyond that: it enumerates the returned fields (id, name, archived, anonymous) and names the upstream endpoint (GET /questionnaires). It stops short of pagination or result-size behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.