Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive, closed-world, so safety is covered. The description adds genuine context beyond them: the result ordering ('newest first') and that unanswered inquiries appear with the answer absent ('when there is one'). It says nothing about pagination, result caps, or volume, which matters for a list tool.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.