What is the CORRECT way to seal or paint new (cured) stucco?

My handyman finished the EXTERIOR of my fireplace/chimney with stucco back in May, and then he disappeared. I am concerned, since I know it requires some kind of sealing or priming against the weather, but am not familiar with stucco surfaces. I live in Texas, where the sun bakes, and the rain pours! Are there any experts out there who can advise me?