I haven’t written a game that used the adjective/noun system, but as an author it feels clunky to think that way. As a player (playing TADS games) it hasn’t ever thrilled me. (Although if a game is designed in such a system, using the system is the way you play.)
I guess I’ll give an example. A couple of days ago I wrote an object like this: (not an exact quote from my game)
The cigarette-lighter is a thing. The printed name is "cigarette lighter".
The description is "It's a ceramic oval the length of your little finger. When you squeeze it, a little flame shoots out of the end."
Understand "cigarette", "lighter", "ceramic", "oval" as the cigarette-lighter.
Understand "fire", "flame", "flaming", "burning" as the cigarette-lighter when the cigarette-lighter is alight.
Dividing up this word list into adjectives and nouns is not completely obvious. “Oval” is used as a noun in the description, but in another piece of text I could just as well have written “oval bit of ceramic”. Then maybe I have an object which is a “wooden oval”, except when it’s an “oval bit of wood”. What does the adjective/noun rule say now about “TAKE OVAL”?
Then there’s the “fire”, “flame”, “flaming”, “burning” set. Maybe the first two are nouns, but then maybe not; they’re kind of adjuncts to the lighter, not the lighter itself. If I was in a room with a bonfire, it would make more sense for “fire” to refer to that, and grammar doesn’t come into it.
The case that the adjective/noun rule is meant to handle is when you are also carrying a “cigarette”. Then you want “cigarette” by itself to not refer to the lighter. But in fact my game has no cigarettes! If it did, I would have described the lighter as a “Bippo” or “snap-lighter” or something to avoid that disambiguation rat-trap.
In I6 I could set up the object to respond to “cigarette” only when the word “lighter” is also used; otherwise it’s no match. However, this is not a great solution for this case. We want adjective-only references to work when they’re not ambiguous.
So, yeah, it’s messy. And to some extent it’s self-fulfilling; you build a game that’s playable in the system it’s built in. I think I like the idea of marking some words as more important – that is, the match is higher-quality if any of those words are used. Don’t tie it to “adjective”/“noun” categories, and make sure it’s per-object rather than per-word.