Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond annotations, the description adds important behavior: it costs no credits, requires OAuth or an API key, and returns the whole board plus the new card. It does not explain revision conflict behavior or failure modes, which are relevant for a non-idempotent mutation.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.