Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare readOnlyHint=false and destructiveHint=false, so the agent knows this is a non-destructive write. The description adds nothing beyond that: it does not explain what the 'config' object should contain, what side effects creation triggers, or whether the operation is idempotent. With annotations covering only the safety hint, the description leaves the behavioral burden unmet.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.