Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare readOnlyHint=false, openWorldHint=true and idempotentHint=false, so the agent already knows this is a non-read, externally-reaching, non-idempotent call. The description adds valuable context the annotations don't: the seal is written to Base until the Privi mainnet, an organization API key is required, and the call is effectively an attestation-producing submission. It stops short of saying repeated calls create new seals or listing failure modes, so not a 5.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.