Yes, using a description referring to the 529 is more appropriate than scholarship. (I updated the original answer). Your exact phrase may not fit, but something similar is fine. According to Pub 970 page 52 "Report it on Form 1040 or Form 1040NR, line 21".
Your son does NOT enter the forms 1099-Q or 1098-T. Use the worksheet from your taxes to find the amount he needs to report (it is based on a percent of earnings over basis). keep a copy of the 1099-Q, 1098-T and worksheet with both your files. There is no worksheet for your son's return, it is simply reported on line 21 with a description to satisfy the filing requirements of the IRS.
