I don't know about a 400EX for sure, but most others came with a tire pressure gauge, a cheap metal spark plug socket with a hole in it that you stick a screwdriver through to turn, a open ended wrench with 12mm on one end and 14mm on the other, a cheap pair of pliers, and one of those screwdrivers that has the end that pulls out of the handle that you can turn around and has a phillips on one end and a flat or slotted on the other end.
I bought a new 400ex in 07 and it came with Tire pressure gage, allen wrench thats fits allens to adjust chain, phillips screw driver and a spark plug wrench. The only thing worth having is the spark plug wrench. The case was a turd! The cap loves to fall off.