Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, and the description adds a genuinely useful behavioral trait: every entry is part of a sealed, signature-verified chain, implying tamper-evidence and immutability. It stops short of describing volume, ordering, or pagination, but for a parameterless read tool this is solid added context.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.