Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral burden. It explains the calculation method (Friis formula) and why first stage dominates, disclosing the mathematical behavior. It does not mention any side effects or destructive actions, but for a calculation tool, this is sufficient.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.