Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The schema presumably only lists unnamed parameters, while the description adds practical meaning: animation_type accepts wiggle/orbit/linear, positions are [x,y,z] keyframe values, and frames are frame numbers. This is genuine value beyond the schema, though alignment between positions and frames could be clarified further.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.