Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations only declare readOnlyHint=false, so the description carries most of the behavioral burden. It usefully discloses that the deletion cascades to the encrypted credential reference, which is not derivable from the schema. However, it omits irreversibility, confirmation requirements, or any error/partial-failure behavior for a destructive operation.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.