When you make a complex family it's hard to give a precise name to some parameters, then you can use the Tooltip to give a single explanation, that's fine. Some times it would be better to include a capture or drawing, this a secondary idea. But moreover, there are some explanations needed to understand the whole family, like a whole-family-tooltip.
Therefore, this idea is to enable a place to give instructions for the whole family, including a picture, either for users or even for oneself after a while