Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden and largely delivers: it discloses the 1-credit cost, the 402 payment envelope for uncredentialed calls, and both authentication routes (X-API-KEY on the MCP connection or x402 out-of-band). This is genuinely useful operational behavior that goes well beyond what a generic read/write hint would convey. It lacks details on rate limits, but the auth and cost transparency is strong.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.