Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
With no output schema, the description does carry the burden of explaining what comes back, and it covers the key point (current config plus per-item layer origin). Combined with complete parameter docs and read-only annotations, an agent has enough to call and interpret it, though a note on output shape or merge scope would round it out.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.