It depends. Are you having just a screening for dyslexia or full psychoeducational evaluation? Honestly either way, several different evaluation techniques will be used. Such as Diebels screening. As well as teasing their reading by having them read passages, as well as cold reads (list of unrelated words, without context clues to use), vocabulary (,having them orally tell the meaning of words), reading comprehension, as well as comprehension by listening.
My daughter had a full psychoeducational eval, so it was a full day of different screenings and exercises, which were disguised as game type activities.
My daughter is dyslexic, and because I could not find a certified tutor, I became certified and now work with other dyslexic children. I actually go next week to do a course for the actual screening part.
If your child is dyslexic appropriate intervention will be important, make sure it is an Orton-Gillingham program, such as Barton, OG, Take Flight, etc. make sure your tutor is trained in the program they are using and certified.