Well why not. The right poet (I mean me! but there are lots of us) can offer an exciting start to your school day (I include guitar and just enough joining in during my morning assembly performances). The children head off to classes with loads of writing ideas already in their heads and I then work with all ages throughout the day.
Teachers tell me that having an enthusiastic practitioner of the art in the classroom has a tremendous effect on them and the children. Together (teachers, children, poet) we produce fantastic new poems and usually share them before home time. After that we do all go home (apart from the teachers who have yet another after school meeting to attend).
A poet in your school? Why not?