Surprised your agent wasn't able to help you with this.
But after your final payment is made, you can go onto the RCCL website to do your online check-in. Once that is completed, you can print out your edocs, which include your luggage tags. Just print out as many as you need and then attach them to your luggage before or when you get to the pier.
Travel Agent/Cruise Specialist w/12 yrs exp and 47 Cruises on 11 cruise lines! Favorites: Paul Gauguin - Tahiti: Uniworld River Cruises - Europe; Celebrity Solstice-class ships; Holland America - 12-nights Baltics & Russia; RCCL - 14-nights Greek Isles, Turkey, & Croatia; Holland America - 14-day Alaskan cruisetour; 10-night Canada/New England cruise; 21 days Hawaii w/7-night NCL cruise; Oceania - 25 days in Asia; more than 3 months touring Europe by train. And many all-inclusive resorts!