The key concept in designing contextualised UI brick help is context.
Think of a user in context and write for the most typical user of the brick in question. Keep it very short. Remember you can add links to information that contributes to understanding in the other documentation types, how tos, concepts, training, etc. This provides for betting staging of the reading experience.
Although six article types are provided, the best strategy is to use one or two. This obliges you to think of the type of content which is the most pertinent. If you end up wanting to use all six types, maybe you will need to talk to developers about where the documentation access is made available, or about the the ergonomics and clarity of the UI.