Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It discloses that the operation is a read (Get), specifies the data source (NOAA), and notes it is free for any purpose. It does not detail response structure or error handling, but for a simple read-only tool this is reasonably transparent.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.