Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false, idempotentHint=false and destructiveHint=false, so the write/non-idempotent profile is covered. The description earns some credit by adding that the backup 'runs in the background,' i.e. the call returns before completion — useful async context. It does not say whether prior backups are replaced, whether there is a backup-count limit, or what the call returns (no output schema either).
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.