Let the editor know how your book ends, don't keep her in the dark. Your editor needs to know them. Avoid using dialogue. You must be sure to have enough conflict to carry your story through the entire book, from beginning to end. And don't forget to include the black moment.
Editors are busy people.
If the editor specifies a 2 pages synopsis, make it 2 pages. Check the guidelines. And it's a good idea to include the word length and target line. Each sentence of the synopsis should unfold the story and move it toward the end. You have approximately 30 seconds to grab that editor's attention.