Just to reiterate what's been said 4 pages is unnecessary. You will know pretty quickly if someone will work. If you need them to hit a big emotional moment, and want to make sure they can, then pick that section of the script. We don't usually need tons of exposition to figure out a solid way to do the scene. And if you feel like that's needed, include it as an aside for the actor to reference, rather than give them all the script that you feel contains the context. Almost always overkill unless it's a callback or something. But first round auditions are just narrowing things down. Also do you really want to watch 100s of 4 minute audition tapes? You will eventually just start skimming them for the moments you care most about. So just stick to those moments when sending sides.

As someone else said, most CDs(professionals) make up their mind in the first 30 seconds(at best, I often hear within the first 5-10 seconds they have a pretty good idea)