Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the annotations (readOnlyHint=false, destructiveHint=false, openWorldHint=false), the description discloses a capability prerequisite (Pro tier blocks automation), a hard failure mode (no project-name fallback, error instead), and a safe preview/confirm gating behavior. These are exactly the behavioral traits an agent needs before mutating state.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.