cook questions

Although we have stayed at Rondel village many times, this year we have my brother and his wife with us and will be staying in a two bedroom villa. It comes with a cook for one meal a day, Have never had a personal cook there before so have a few questions about it. I believe that we give him or her the money to pick up the groceries needed. We have no idea what to tip or when. I believe the price of having the cook is covered in what we paid for the villa but not sure how it works, Also being my brother Jim and his wifes first time to Jamaica , we want to turn em onto some of the great places to eat In Negril so probably wont utilize the cook that much. I dont know if the cook would be turned off by that or if its common place. So just wondering how it all works . TY S&K