Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description partially carries the burden by naming four outputs (profit, true CPM, break-even rate, verdict). This gives some sense of behavior, but it does not disclose whether it is a pure calculation, what assumptions are made, or any limitations. It adds basic output context but lacks depth.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.