"Mr. Lukeman, If I can describe my plot in two sentences, is it okay to use the third sentence in that paragraph to describe the voice in my writing or is that amateurish? Thanks a lot," Donna Voss
I would really suggest sticking to the basics of what is necessary in a query letter, and keeping it as brief as possible. If you can summarize your plot in two sentences--great. That does not mean you should add a third sentence just for the sake of it. And in this case I would not attempt to describe the voice of your writing--that is the sort of thing that agents must judge for themselves, and which will come out in the writing as they read it. Voice is also subjective, and they must be left to come to their own conclusions.