Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds meaningful context beyond that: results are ranked, each hit carries a short summary, and the URI must be handed to fetch_qencode_doc to get full content. It does not add much about limits or failure modes, but the annotation bar is already met.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.