DWP Phone call mandatory reconsideration rejected

One thing I can't seem to grasp is how to write a brief section 5 on the SSCS1 form. I have written a detailed attachment, but not sure what I would need to put on a brief one which would be accepted by the DWP for a tribunal. On the detailed one which I was advised to send at a later date, I have made my arguments and laid everything out so it is easy to read and compare to my medical report. I worry how brief the initial section 5 should be as I do not want it rejected. Would I just write a short paragraph saying what I disagree with and why without too much information? For example I have many points on my detailed section 5, would I mention them all in a brief version? How should I give reasons that I disagree without showing my hand too early? Sorry if I don't make sense, just worrying now as I have a few days to get it all done and posted. I have looked at example SSCS1 forms on here, but still confused. Thanks