Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint: true, so the description does not need to repeat that. The description adds context about what data is included (lists, cards, deadlines, links) but does not disclose any additional behavioral traits such as performance, rate limits, or permission requirements. Since annotations cover the read-only nature, a 3 is appropriate.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.