Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100% and the single parameter carries its own description ('What the AI feature does, who uses it, and what it must never do'), so the schema does the heavy lifting. The description adds only the framing 'planned AI feature' and does not enrich the parameter beyond that, making the baseline 3 appropriate.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.