Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare read-only, idempotent, open-world, and non-destructive behavior. The description adds context beyond that: solar times come from the weather pipeline's astro product, it returns a 14-day calendar with Today/Tomorrow offsets, and it accepts a place name directly. No contradiction with annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.