I know that you ask that writers include the first 3-5 pages of their manuscript with a query. Are agents expecting to see a hook in those first few pages? A conflict that is already established? Or are they just assessing the quality of the writing?
This is akin to asking if you want your prospective spouse to be smart or good-looking. One can be objectively measured; one is in the eye of the beholder. And really, you want both. Right?
So, when I read those first pages I'm not reading with a checklist.
I'm just like someone picking up the book at Murder By The Book in Houston Texas: reading the first page.
I'm flipping through pages just like a book browser at Aunt Agatha's in Ann Arbor Michigan is.
The only question in my mind is "Do I want to read more?"
You can entice me in a number of ways. A good first line is always a good bet. Something surprising works well. Gorgeous syntax does too.
Eventually it all has to come together, and much like when you met your honeypie, you come to know it's love, even if you don't know why.
You're trying, as many writers do, to make a subjective process more rational and objective. How agents choose books will never be like that. All you can do is write an awesome book and query till you find the agent/s who recognize Awesome when they see it.