After completing a novel, writers must create a synopsis—a concise, spoiler-filled summary of the story's main characters, plot points, and resolution—formatted in third person, present tense, and typically 500 to 1,000 words long. This synopsis is crucial for agents and editors to understand the novel's structure and character development and is included alongside a query letter and excerpt when submitting work for publication. Writers can develop their synopsis from their novel outline or chapter summaries, ensuring it clearly presents the narrative arc and concludes with the story's ending.
https://www.literatureandlatte.com/blog/how-to-write-a-novel-synopsis