So my ds was a lot younger when he had his assessment (3ish) but I imagine there would be similarities.
When we got to the assessment I had to fill out several different forms about ds's development and behaviour.
Ds has to play lots of games. They set up a course with lots of different physical activities which he had to do in order, involving, climbing (rescuing a toy from a high place), swinging, balancing, going through tunnels etc. he then played a series of games that tested his fine motor skills, like using a tool to screw things into a board, puzzles, finding toys in theraputty etc.
The therapist was looking at how he followed instructions as well as if he had sensory difficulties with any of the tasks and whether certain activities made things easier or more difficult for ds ie, was he calmer after swinging.
After the assessment the therapist went through all their findings with me. I got a report a couple of weeks later.