auto-add feature in headless debian?

I run one of my databases on a headless debian box and currently use the client to access it. I stored a bunch of books in a directory called 'to-add' and successfully add those books using the calibredb command:

Is this is the only method of automatically getting new books added to the library? Run this script using a cronjob?

I had thought simply loading up the library would do it, but I guess it makes sense to let the user auto-add the books on their own.

Thanks again