Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full disclosure burden. The explicit 'read-only' qualifier is genuinely valuable and prevents the agent from assuming side effects from a tool named 'health'. However, it does not disclose what the check actually probes (reachability, versions, model availability), failure behavior, or whether an unreachable provider could make the call hang.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.