Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already indicate read-only, idempotent, and non-destructive behavior. The description adds a meaningful behavioral requirement: the agent must quote licensing and privacy statements exactly as returned and never paraphrase them. This goes beyond the annotation coverage, though it does not describe response formatting details.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.