The choppiness may result from jumping around in an effort to account for all the details and characters. Synopses aren’t exhaustive, particularly if the story is a complicated one with a large cast. When the editor is ready for the full skinny, she’ll read the manuscript itself. For now, she’s looking for a summary of your main plot and main character arc. That’s it. So, in two or three pages, tell her what the main character needs or wants to achieve, what threatens the MC enough to kick-start the story, what steps the MC takes to achieve that goal, and what challenges the MC overcomes to get there. Walk the editor through those chapter by chapter, using direct statements. You’re telling at this point, not showing: “In this chapter, MC does X and it worsens her problem by X.” If you’re well short of 2 to 3 pages, you can trace a subplot through the chapters, too. But only do that if the subplot is essential to understanding the main plot’s path. After that framework’s in place, go back and massage the chapter rundown into a smooth story of your story. A hint of your narrative tone can sneak in now, and you can work in sentence variety. The result is a synopsis that does its job and shows off your writing mastery at the same time.