No one likes to read a manual; your guidelines should follow the same flow of thinking as those submitting. This will improve engagement and ensure candidates aren’t put off by a wall of text. The basic building blocks of your story should follow the structure below.
Start with who should submit, to make sure that only the relevant candidates read on; then let them know what’s in it for them, what effort they will need to make to be considered and finally any support materials which are significant should a candidate apply.