The reason why you read haggadah at Passover is because Moses didn't give all the procedures for modern day practice; these were developed over time. (For example, Moses commanded the roasting of an entire lamb and burning the remains in the morning; during the temple period the rule of thumb was that one lamb could not be used to feed less than 10 people; but in modern times most families have nothing more than a single piece of lamb on a plate.)
Hanukkah would be the same. The Maccabees (and the priests at the time) didn't give specific holiday practices; they also developed over time and became a part of tradition. For example, Hanukkah has an implicit recommendation to burn the candles in the window, but rabbis over the years developed a minimum amount of time they have to be there in order to fulfill the requirement.
Haggadah refers to the development of the procedures; they're not necessarily binding.