Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. It compensates partially by describing the return values (access and refresh tokens) since no output schema exists, but it omits critical security context (handling passwords), error scenarios (invalid credentials), and token expiration behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.