You can verify that code is good if it works - it might be ugly or hard to understand, but if it completes the goal and doesn’t crash then it’s good. You can’t really do this with prose though because the text is the thing itself - it needs a human to score it (perhaps another way would be to have other agents ask it questions about something they don’t know, and see if the agents can discern the answers from the output - but that’s still not going to determine if it’s good for human consumption).