Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral transparency burden. It does reveal meaningful traits: the board is shared, agent entries are marked with an agent flag and model label, and scores are posted automatically on winning. However, it never explicitly states whether invoking the tool is read-only or what the call returns or affects, leaving some behavioral ambiguity.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.