A better way of saying this?

I received a job offer, but there's a difference between what was discussed and whats being offered in offer letter. I'm ok with both the roles but how should I clear it, what should I write? This is what I came up with..

"I have a little doubt about the role I'm being offered, is it abc(as we discussed and as mentioned in mail) or xyz(as mentioned in the offer letter)?"

There sure is a better way and I would like to know about it.