Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare read-only, idempotent, open-world, non-destructive behavior, so the bar is lower. The description adds genuinely new context: the score is 'derived' and 'not independently verified' (an important trust caveat), and it discloses a $0.01 per-call cost, which matters for cost-aware agents. It stops short of explaining freshness, score derivation method, or failure modes.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.