Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden, and it does disclose the key side effect: the current JWT token is invalidated, which tells the agent the session becomes unusable. It omits other relevant traits such as whether an already-logged-out or invalid token errors, and whether invalidation is server-side only.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.