Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already establish readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description still adds genuine value beyond them: it declares the call is credit-free ('Free') and that authentication via the user's Cotlet API key or sign-in is required, which matters for failure handling. It does not say what shape/format the response takes, but the field list largely compensates.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.