What do precision and detail actually mean in an essay?

Hi, I think what the marker/teacher is trying to say (if they haven't/wont clarify with you) is you need to be more specific and clear with what you're writing (straight to the point, no wandering, etc.) and for detail I think they just want you to say more about what you're arguing/saying. Now I'm not a teacher and this is pretty general as it varies across subjects so I'd suggest seeing if whoever is giving you this advice is willing to clarify and baby even show you examples of what they mean.