Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden, and it does disclose one meaningful behavioral limit: Base's public RPC has no mempool, so no pending-transaction data will be returned. That is genuinely useful context beyond the schema, but it says nothing about freshness, caching, or rate limits on the call itself.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.