Debbie B. answered 05/20/19
Proofreading and Editing Specialist with 20+ years of experience
This is something your chosen editor will do for you. The agent wants a professional to convey how much work the manuscript will likely need. He's looking for an impartial assessment of not just your grammar and style but if the storytelling is on point, and, I might add, how easy you will be to work with (as much as that can be surmised). I happen to be a manuscript editor, if you need one...! In any case, good luck!