Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations (readOnlyHint, idempotentHint, etc.) already convey behavioral traits extensively. The description adds return field details and sorting behavior but does not disclose additional traits beyond those. With rich annotations, the description's incremental value is modest.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.