Agents like to submit a full package to publishers, which includes the synopsis, so always give it to them. Editors may or may not want a synopsis—but you won’t know your targeted editors’ habits, so again, give it to them. Some editors won’t read it because they prefer the story prove itself. Others want to know your plans after you’ve intrigued them with your query letter and sample chapters. As with anything you write professionally, your synopsis should have a hint of personality, and, yes, that personality should suggest the tone of the book. Write it using omniscient POV, and—brace yourself—tell, don’t show. Wow, I don’t advise that often! But the point of the synopsis is to summarize the main themes and plot points and to state how the main character will change in the course of the story. Save the details and the full cast of characters for the manuscript. Striving for one page, single-spaced, should force you to stick to the main happenings. If you dread summarizing your 200-page story into one page, then trade manuscripts with someone in your critique group and write each other’s initial synopsis drafts. Then trade back and modify your buddy’s version to suit your own voice. However you get the synopsis done, DO get it done. You’ve moved mountains to finish the manuscript and make it submission-ready; don’t let one final page take the wind out of your creative sails.