Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), and the description adds real behavioral detail: it recomputes a digest and verifies a signature against the house public key, and enumerates the attested fields returned. It omits what happens on verification failure (error vs. a status field), which is the main behavioral question left open.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.