Screenwriting : On Screenwriters and Agents, a practical discussion by Ben Cahan

Dan, that is why it is important to impress somebody, even if that person is some assistant to some producer, or a producer who has only made shorts. All of those folks see loads of scripts, so if yours can stand out, perhaps they will move your script into the hands of someone who could get it really considered.

As a representative myself, I of course believe that the work we do to be extremely important in establishing oneself as a professional screenwriter, but there is a good deal of self-generating required by the aspiring screenwriter. Getting out there and read, honing your craft, entering and being selected for high end screenwriting contests, or just getting a great referral from an assistant, coordinator, jr. exec whose taste is well respected. That kind of referral is taken very seriously by agents and managers, especially if you can create a little bit of fomo, by having the referral made to a couple of reps who believe they have to compete to be in business with you.

Often getting that referral does mean some rewrites or pleasing the person thinking of actually making the referral, but if your advocate is clearly on your side, wanting the same thing from your script as you do, keep an open mind and work together, the worst that can happen is that they don't feel it is ready for them to make the call or send the email to their rep or producer contacts.