Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the burden of explaining behavior. It does disclose that the tool returns detailed weather information including a multi-day forecast, which helps. However, it does not describe the response format, specific fields, data source, or update behavior, leaving important behavioral details unspecified.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.