Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the burden. It accurately conveys a read-only lookup, but does not disclose potential dependencies like location, calculation method, or timezone, nor any caveats about what 'today' means. This is moderately transparent but could add more context.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.