1) The format is NOT professional (which is a sign of rank amateurism, since professional format is easily ascertainable from any available script—and the Internet is full of sites that offer them free).
2) The writer hasn’t bothered to proofread his work. It’s filled with spelling errors, typos, and repetitions.
3) The protagonist isn’t clear after the first five pages. You still don’t know whose story you’re reading.
4) Even if you know the protagonist, by page 10 you still don’t know what his dramatic problem is—or you aren’t “involved” with him. You don’t know why you’re reading his or her story.
5) By the end of the script you neither know what the dramatic problem was nor how it’s solved by the story.
6) The obstacles to the hero’s mission aren’t strong enough, clear enough, or interesting enough.
7) The Point of View is unclear throughout the screenplay, or is “all over the place.”
8) The protagonist and antagonist aren’t written with stars in mind. Once we love the story, Hollywood wants to know: What great actor or actress will desperately want to play this role?
9) The story lacks credibility—characters don’t behave the way people like they’re supposed to be would behave in the situation you’ve created.
10) The script is filled with clichés, or with on the nose expository dialogue and narrative.
11) The script isn’t 100% visual, filled with stage directions that aren’t “visual.”
12) The protagonist doesn’t grow from the beginning of the story to the end.
13) His or her antagonist isn’t clearly defined or singular enough to make a castable and saleable drama.
14) The climax and conclusion of the script aren’t strong enough, positive enough, and/or satisfying enough to warrant the investment of the reader/audience’s time.