Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered. The description adds value beyond them by stating the auth prerequisite ('Requires Shield login') and that results reflect what Shield 'currently holds', signaling live authoritative state rather than a cached or computed view.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.