Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With destructiveHint and idempotentHint already present in annotations, the description adds useful behavioral context: only the expected output is replaced, the file pairing is immutable through this operation, and deletion/re-adding is the route for pairing changes. This goes beyond the annotations without contradicting them.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.