Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the safety profile (readOnlyHint, idempotent, destructiveHint=false, openWorld), so the description doesn't need to. It still adds genuine context: 'No API key required' and 'limit caps results'. It doesn't say whether the list is stable/cached or what happens if limit exceeds available platforms, but with annotations carrying the safety load this is solid.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.