LLMs can be great at providing book reccomendations based on natural language queries like descriptions of past books you've read or decribing the type of genres or plot you want out of your next read.
However, sometimes reccomendations by these LLMs may not exist or are simply not carried at your local library or book store, leading to a less than ideal experience.
Therefore, if given a database of all avaliable books this program can check the LLMs reccomendations against that database. Thus ensuring that those reccomendations are real and available.