As discussed above, action is very personal. When I do the final setup, I make sure the G string can go as low as 3/64" before bottoming out. This insures that the player will have enough range to tweak their bass from a very low action, to a moderately high action.
I consider very low to be 3/64" on the G and 5/64" on the E. On the high side, my range would be 3/32" on the G and 4/32" on the E. This is measured at the 12th fret, holding the string down at the first fret, and measuring from the bottom of the string to the top of the 12th fret. Add an additional 1/64" for a B string.