whole wheat crust

Is your dough fairly high hydration? If the surface of the dough is moist/sticky, it's very difficult to get a nice straight cut, and what you get is the jagged edges you describe. This is why ciabatta isn't scored: it's just too wet, and besides, it doesn't need scoring because the surface is so elastic. It expands all over, rather than bursting along a seam or a weak side.

It appears to me that you didn't get a lot of oven spring, since the scoring didn't expand a whole lot. Is that just the angle of the photo, perhaps? Do you steam the oven or spray the loaf as it goes in?

I would try to form a little bit of a skin on the loaf as it proofs. Don't cover it with plastic. rather use a floured towel. You could also let it rise upside down in a banneton again with lots of flour. (I use some cheap baskets with a floured piece of canvas.) The idea is that the flour dries out the surface of the dough, and prevents sticking to the cloth. Rolling the high hydration dough in flour is also a good idea (looks like you do that already).

What are you using to score? The specific instrument isn't so important, except that it be very sharp and not gummed up. I've used a razor blade, a chef's knife, a bread knife, and a serrated tomato knife. Wetting the blade helps avoid snags (and keeps it clean), as does a quick hand. The serrated blade was the easiest to use, especially for straight cuts, and the double edged razor, bent slightly, was the best for the angled cut in baguettes.

Finally, you might try leaving the bread in the oven for ten minutes or so with the door open, to dry out the crust.