Tip#4 to trim a synopsis—relevance

Cut absolutely anything that does not have direct impact on the main storyline. Be ruthless.

Don’t leave things in because they pertain to a subplot.

Don’t go off for too long (more than a few sentences) on a red herring.

Don’t include character backstory that doesn’t absolutely need to be there in order to explain the main plot.

Don’t describe characters’ physical features unless it’s a vital element to the story (such as the hero mistakes a red-head for the heroine).