Tags and Title are required entries to save a web map in AGOL and Portal. It should be easy to extend the code behind that functionality to require filling out the rest of the fields in the Item Description (Item Details). I would like to see the Item Description be a required entry to eliminate the ability to save web maps, services, or apps without a description. Forcing these items to be filled in before enabling the save, will help eliminate the lack of documentation describing an item. This will encourage best practices and stop bad habits (of not providing a description of the GIS resource) before they get started.
Even better if you make this functionality something an organization can enable if they choose!