Only what is needed to make the state machine work. So it is dependent on the design of your state machine. If for example state 1 is called when a variable is clear and state 5 is called when that variable is set, then in effect no extra information is needed. But if state 1 is called regardless of the state of that variable (and of course is dependent on the contents of that variable) then there needs to be additional information somewhere that indicates whether or not that variable is set.