Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations only provide openWorldHint, so the description must carry the burden of behavioral disclosure. It reveals the side effect of creating a backup and that an operation_id is returned, but it does not state that the backup is likely asynchronous, how long it may take, whether it consumes storage quota, or what happens if a backup is already in progress. For a mutating tool with no readOnlyHint or destructiveHint annotations, this is a meaningful gap.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.