hey @nbh,
I’m note sure to understand your question.
but, it’s true that the documentation for created a new functions (a primittive) such as ‘dance’ is not very clear…
I’m work to improve this part, but I have no time for that 
here is a notebook to explain how create and add a primitive. how-to_Primitive.ipynb (37.2 KB)
I’m sorry, because this notebook is actualy in french… actualy this notebook are just a draft …
Moreover, you can find other doc about that: e.g https://github.com/poppy-project/pypot/blob/master/doc/primitive.rst