Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Adds real context beyond the annotations: data is preserved, the task is restorable from the archive, and archiving a dated repeating task spawns its next occurrence. That side effect is non-obvious and not derivable from destructiveHint=false/true alone. It stops short of stating permissions or failure behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.