Interesting seeing this from the other side. Usually the student/applicant helps out his recommendation-writers by providing a little extra information about himself. If there’s still time (sounds as if there isn’t), try asking him what he wants out of college, what he wants to study, why he wants to go where he’s applying to, etc. If possible, ask him for a look at the essays he wrote for the applications, and it should help you get a better sense of who he is.