The ADOS-2 series of tests (depending on the age of the individual) includes answering some questions asked by the diagnostician, putting together a puzzle, narrating a book which has no words, playing a game, taking breaks, pretending to brush teeth, completing at least one written quiz and being observed by one or more diagnosticians. It takes about three hours to complete (unless additional non-autistic characteristics need to be assessed, too). I was able to trim my ADOS-2 module 4 assessment to just two hours because I arrived prepared with a detailed list of my lifelong characteristics with examples. My diagnosticians really appreciated my work and used it in their written assessment and diagnosis.
Overall, the ADOS-2 series of tests are actully kinda fun.