If you work in a large law firm with recruiting infrastructure, two assumptions driving the recruiting process are that students know who you are (large firm) and why they want to work for you (training and money? money and training?). That a particular candidate may be ill-informed, unqualified or otherwise ill-suited for your practice is a subject for another day.
If you work in a small firm without a marquee specialty practice or a small firm in a small town, recruiting may be difficult for you, in part because law students who have barely learned to distinguish torts and contracts may have trouble understanding who you are and what you do.
In the lawyerist.com post Hire the Right Law Clerk: 4 steps, I suggest a process that connects you to career services professionals, and helps them help you give students useful information for the applications for your law clerk position.