I guess it all depends on how you word it. Instead of coming across like you're nervous and fishing for any clue that might give you a leg up, you can always put it as though you are coming from a position of strength and just trying to be professionally prepared. So why not call him and try something like:

In order to be properly prepared for the practical portion of the interview, I was curious if I should bring my own toolset and/or laptop or will everything required be provided for me? Also, I'm not asking for any advanced info, but during that portion of the interview, will the scope be clearly defined as it would for a real client engagement?

This shows that you understand what it means to have a practical portion, that you are not afraid and also that you understand the business aspects of a pen test.

Purely by accident, your interviewer might give away some subtle details that can help you focus.

As always, this is advice. Take it as is. 

Good luck,
Don

Great advise Don