When you reach the end of what can be broken down, stop.
For example, the French word "maison" (house), has no further breakdown possible. There is no further useful information which can be added by breaking the word down further. Therefore leave the Literal Breakdown empty.
Do not add in the Literal Breakdown section the word itself. For example, "chien" (dog in French) is not the Literal Breakdown of "chien". The word "chien" does not have a Literal Breakdown. There is no further breakdown of "chien" which is possible. Indeed, it would be a mistake to put the word "chien" into the Literal Breakdown for "chien", because this just creates an infinite loop; confusing for the student, and it can also cause problems for the software.
So, breakdown to finer and finer detail, but when you reach the limit of what can be broken down, stop.