Sam Smiths’ pubs have similar (but covering more things) rules - see this example (currently not open, but the details are still there). I originally mapped that here with the prohibitions as per access tags (“games_console=no”) but another mapper objected. Description tags are great for ensuring that information doesn’t get lost, but if “no laptops in coffee shops” is becoming a thing then it makes sense to have a specific OSM tag for it.
You could try searching taginfo for previously used values, but I’ve had a look and can’t see anything obvious. Maybe someone will suggest something that has been used other than description.
It’s certainly OK to “just make a tag up”, with the obvious caveat that you don’t want to use something that is already used for someone else.