Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must carry the transparency burden. It discloses that charts are conditional and that the output is a summary, but it does not mention potential performance/latency implications of a combined call, data freshness, or any side effects. It is not misleading, but it is minimal.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.