Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive behavior, so the bar for added value is high. The description goes beyond this by disclosing that claiming is free and costs no gas, that the signature is proof of wallet ownership and not a payment, that the signed result expires in 5 minutes, and that no private key should ever be shared. This is rich behavioral context that an agent needs to handle the tool safely.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.