Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare read-only, idempotent, and non-destructive behavior. The description adds meaningful context beyond this by explaining the buyer/supplier distinction, the 'top' selection criteria, and the inclusion of act counts and EUR totals, which are not covered by the annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.