If they have shelves on the side to capture the bead, they are tubeless ready. Just about every rim made in the last 2 years is tubeless ready. Tubeless ready are actually fine with tubes. You have to push the beads into the center groove, which, in many cases, is deeper on tubeless rims than it is on older rims.
There is a lot of variability in rim size, and there always has been. Some of the rims made for production bikes are smaller than they should be, because it's easier to get tires on at the factory and the vast majority of bikes are still shipped with tubes.