Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations and no output schema, the description carries full burden for behavioral transparency. It only says 'Remove user segment,' which implies mutation, but fails to disclose whether the action is reversible, requires specific permissions, affects other segments or sessions, or changes the binary structure. The agent is left guessing about consequences.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.