NodeData based classic plugin classes can implement NodeData::GetDDescription(). This allows to dynamically add parameters to the element's parameter description. This description is then used by Cinema 4D to define the parameters that are displayed in the Attribute Manager.
NodeData::GetDDescription() corresponds to C4DAtom::GetDescription().
When NodeData::GetDDescription() is called it is supposed to fill the given Description object.
The arguments of the function are:
Details on how to handle a Description are described in Description Manual and Description Settings Manual.