Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure. It only says the result is an image; it does not mention permissions, device applicability, side effects, failure modes, or whether the screenshot reflects the current screen. This is minimal disclosure for an unannotated tool.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.