Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare this a safe, idempotent, non-destructive read. The description adds material context the annotations cannot: the model table and days 8–14 are gated behind SnowSure Pro or a saved resort, and unauthenticated/free callers receive only the seven-day blend. That tier-gating disclosure is genuinely useful.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.