I think that "brilliant" possibly fits here. I suppose then, although the terms "brilliant" and "spot on" aren't typically considered as one of the go-to translations for "κουκλί", they could work on some occasions.Κουκλί! Πολύ ξεκάθαρο κείμενο.
I neglected to add that "perfect" might be a better fit in this particular case.I think that "brilliant" possibly fits here.