Mine sometimes goes to 710 or so despite nothing negative on my report and 10+ years of regular student loan payments, solely because I churn frequent flier and cash bonus credit cards every 9 months or so.
I think you really just need the report, which the tenant can get for free and email to you. Check the “negative” section to see if there are any real problems.
People who have no loans and never got a credit card often have low credit scores.
