And that it’s legal (though rare) to use commas in something like “take ball, bat and glove”. (If you want to allow the serial comma in there you have to do this.)
Also, the comma itself can be used as a command separator, so that “JUMP, JUMP” will have the player jump twice. (I think this may also be pretty rarely used.) Fortunately here you probably only have to worry about the bit after the last comma–a player who types “jump, paul, look, jump” deserves whatever happens to them.