In one page they certainly dont want just a list of duties. Sounds like its a more philosophical thing - do you view stage management as a craft, as an art, as a creative role, as the coordinator of things technical? Are you the integrator or the arranger? Do you plan, or react, or both? What are the key qualities that you bring to the role and how do you see the role relating to the project as a whole... and what smccain said!
Actually I think this would be kinda hard but fun to write, and a good exersize in re-examining what it is you are choosing to spend much of your energy on. I dont suppose there is any 'one true way' to write /format it - much as there is no one true way BE a stage manager.
Good luck with it.