You can add as many qualifiers as you want (fiction/non-fiction only, good for a summer day, etc.). I had it explain to me why it recommended each book and the logic checks out.
I used it to recommend a book to my friend too based on their interests, and to find a book that we might both like so we can read it together.
Edit: as others point out it may require some “prompt engineering” to correct it from making recommendations by the same authors or well-known bestsellers. Try giving it a nudge in the right direction in response
Edit2: by “better than any website” I meant other algorithmic recommendation websites like Goodreads, Tertulia, TheStoryGraph. It’s a given that these algorithms will never deliver the serendipity of finding something you never would have guessed you’d like, nor the meaning of a recommendation by a friend. I just mean that among the algorithms, this one is clearly the most sophisticated, and is helpful if you know what you like