I might get a second opinion if I were you. I had a slight Rotator Cuff tear about 3 years ago and did Physical Therapy and it got better. Had to do it again after I was dormant for too long and my Shoulder froze. Lately I wasn't exercising it again and it got sore again and I started exercising again and the pain subsided.
So it depends on how bad the tear is. I never had Surgery but then again the Doc said the tear was not that bad.
If by chance it is bad enough then what I have heard is that Surgery is the only way to repair a badly torn Rotator Cuff.
If it's bad enough for Surgery then you will have to do Physical Therapy on your Shoulder for awhile afterwards.