To assess cut quality more info is definitely needed, the crown and pavillion angles are crucial for this, you can find these on the cert - angles for GIA and AGS and % for EGL. The grading lab has an influence on the value of the diamond too. This diamond from the info you have given could well be very nice and the depth is fine, so not too shallow at all. I too would advise getting an independant appraisal to make sure the diamond checks out, especially if you are within the return period. Also this is an E colour so the price will be higher for the colour too. Congrats on your diamond and we would love pictures if you can!
it is a round brillant cut stone, and graded by GIA. but i don''t see any info for the crown or pavilion. any sugguestion where i should get it appraise in nyc. will post pic once he decides to propose. thanks