Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must fully disclose behavior. It clearly indicates a trigger action that causes a visual effect on all screens. The simplicity of the tool (no parameters, no side effects mentioned) means the description is sufficient for understanding the outcome.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.