Analysts Read from the beginning (the Title) to the end without any sneak peaks ahead. They don't want to accidentally read any spoilers.
The book "Writing Scripts Hollywood Will Love [An Insider's Guide to Film and Television Scripts That Sell]" is by Katherine Atwell Herbert, an actual professional script analyst; she was the first reader for Robocop and Bill and Ted's Excellent Adventure.
The third chapter of that book details how script analysts work, and YES, they read from the beginning to the end; take notes along the way for themselves, and so on.
They may take overall impressions just from the title, page count, formatting and "density" on the page, but they do not read in the middle because they don't want to see any reveals or spoilers: They want to judge tension and open questions as they go, to simulate the experience of a seen movie.
On titles: Chris Meindl, reader for MGM:
"Titles are sometimes an indication that the writer has given this project more than a moment's thought. Good titles will have resonance or call up associations. Too many scripts have two word titles that sum up a high concept story and we already know how the story works before we even read it."
She says nearly all readers look at the length; if it is not between 100 and 130 pages, the reader suspects the writer's professionalism, and assume "the writer does not know how to tell a story in the context of a film".
The script analyst will also notice (and become biased by) any typos, non-standard fonts being used, missing punctuation, horrific grammar. All are unprofessional.
Most script analysts have made much of their judgment within a FEW pages:
For a six year veteran at a major studio the most common script problem is, "predictable people relying on clichéd events." In these scripts, "you know what's going to happen in the story after only a couple of pages," she adds. She hardly needs to read further, but of course, she does.
For some analysts the first few pages of a script are indicative of its overall merit. Meindl has found that, "You know in the first few pages if you're in the hands of a capable writer."
A senior VP of production at Twentieth-Century Fox is concerned with neatness, spelling and grammar and is also put off by scripts that, "are too dense. There's not enough white space on the page." Or as Allen Page, an analyst at Warner Brothers who has also taught various film courses, remarked, "a script should be easy on the eye. It should be script-like rather than novelistic." Being too dense means there is too much description, which means the writer is probably overwriting.
The book is worth buying if you are serious about script writing. Later in Ch3 she says:
Nonetheless, the readers stick with it to the end, and turns each page hoping to find originality, something unusual that will spark their interest, or a creative approach to the plot development, the hero's problem, the description of characters and the theme. Most of the time they don't find it.