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, and a one-line 'get' sentence only signals a read operation. It does not define what 'visible' excludes (hidden, offscreen, or non-CanvasItem elements), what the return value looks like, or edge behaviors such as erroring when no game is running.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.