Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=true, so the safety profile (non-destructive mutation) is covered. The description adds no behavioral context of its own: nothing about idempotency, what happens if the venue is not currently a favorite, or auth requirements.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.