Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover readOnly/idempotent/openWorld safety, but the description adds real context: dimensions default to all, each collection paginates independently with the same limit/offset, missing catalog records may still carry ranking or revenue data, and soc2Disclosure values are vendor claims not certifications. That is meaningful behavioral disclosure beyond 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.