They're on their way from Japan with some other stuff, so will be a while. But yes, that's what I got them for, although it's at least possible to retighten loose ones with an open end wrench put on at an angle (not ring ends due to the chamfer).
I was wondering if chamferless wrenches existed and found
this post on here about them. I know flat/chamferless sockets are available in larger sizes for suspension stuff, and of course you can always grind stuff down.
I don't know how these ended up on my bike. eThirteen crankset with SRAM chainring, so blame one of them. I had the bike shop fit a smaller chainring (also SRAM) from new, and the empty box for it I got contained normal chainring bolts/nuts.
Come think of it, the bike shop probably used one of these cut stamped chainring bolt spanners which suits all types, and has no chamfer. Never had a bike with chainring bolts before, so didn't remember these things existed. The KTCs will be nice to have anyway and they were cheap.

(not my photo -
source)