The whole purpose of a DSL is to make the whole system simpler, by separation of concerns. That is, the DSL as a language is still much simpler (fewer data typ

The whole purpose of a DSL is to make the whole system simpler, by separation of concerns. That is, the DSL as a language is still much simpler (fewer data types, fewer elements, fewer rules, etc.) than the whole application, which is built using that DSL. So I'd expect the DSL's documentation to be short and targeted at the people writing within that DSL. If the DSL's documentation is more complicated than the original problem (spec), it failed at its purpose. BTW, ultimately you have a chain of languages, such as: Spec <- DSL <- Meta-DSL <- ... <- programing language But in the end, that chain goes from complex/specific to simpler/generic. So the documentation effort should shrink dramatically from one step to another (or your system design is seriously flawed). Usually, the Meta-DSL or Meta-Meta-DSL is already the plain, generic programming language you are using. And that one requires no documentation writing at all, because is already documented and widely understood.