Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations mark this as a non-read-only, non-destructive mutation, and the description adds real behavioral context beyond that: it discloses the concrete effect (removing the key from the keychain) and the consequential asymmetry that unlocking requires the user. No permissions or reversibility details, but strong for its size.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.