Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the behavioral disclosure burden. It usefully states that open-meteo is the source, no API key is needed, and the call costs $0.002. However, it does not clarify failure behavior, invalid-city handling, rate limits, or how the lat/lon claim maps to the actual schema.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.