Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden. "Remove" implies a destructive mutation, but it never states whether the removal is reversible, whether it deletes stored configuration or only the registration entry, or what happens if the name does not exist.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.