Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the annotations' destructiveHint and idempotentHint, the description explains the actual consequence: no recipe is lost, and recipes only in that cookbook move to the default. This is exactly the behavioral context an agent needs before invoking 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.