Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must carry the behavioral burden. It does add meaningful context by clarifying that the angles are 'absolute' and expressed in 'radians.' However, it does not disclose side effects, response/return behavior, or angle normalization, which keeps it at a solid but not rich level.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.