Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must disclose behavioral details, but it only states the action. It doesn't explain what happens if the list doesn't exist, whether the operation is reversible, or what the response is. This leaves critical safety and success/failure behavior undocumented.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.