Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds genuinely useful behavior the annotations cannot: whole lower-priority items are dropped to fit token_budget and the dropped items appear in "omitted", and unresolved terms are listed rather than guessed. It does not mention failure modes or what happens when nothing matches the task.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.