When we get to the point where LLMs are able to invoke these tools for a user, even if that user has no knowledge of them, and are able to translate the results of that reasoning back into the user's context... That'll start to smell like AGI.
The other piece, I think, is going to be improved cataloging of human reasoning. If you can ask a question and get the answer that a specialist who died fifty years ago would've given you because that specialist was a heavy AI user and so their specialty was available for query... That'll also start to smell like AGI.
The foundations have been there for 30 years, LLMs are the paint job, the door handles, and the windows.