Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the safety profile (read-only, idempotent, non-destructive, closed-world), so the bar is lower. The description still adds real behavioral content beyond them: the empty-list-with-note response and the disclosure that results are not ranked by commission, which signals the ordering is not commercially biased.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.