You might as well just write instructions in English in any old format, as long as it's comprehensible. Exactly as you'd do for human readers! Nothing has really changed about what constitutes good documentation. (Edit to add: my parochialism is showing there, it doesn't have to be English)
Is any of this standardization really needed? Who does it benefit, except the people who enjoy writing specs and establishing standards like this? If it really is a productivity win, it ought to be possible to run a comparison study and prove it. Even then, it might not be worthwhile in the longer run.
This standardization, basically, makes a list of docs easier to scan.
As a human, you have a permanent memory. LLMs don't have it, they have to load it into the context, and doing it only as necessary can help.
E.g. if you had anterograde amnesia, you'd want everything to be optimally organized, labeled, etc, right? Perhaps an app which keeps all information handy.