These are the side pockets. I already added the zipper to the one on the right. Well, after staring at them for a while, and thinking about ways to make some kind of tool belt or fannie pack, first I tried this:
...and did not like how it looked. And then, I tried joining the side pockets together, like this:
...and I still don't really like how it looks. But this is an iterative process. Stay tuned.