I probably wouldn't say "you're good" to tell someone that they are a good or nice person. And, if I wanted to tell someone that they were good at an activity or sport, I would probably say, "hey, your're good at tennis."
One thing I would consider...was this spoken by someone learning English or by a native speaker? If it was spoke by a native speaker, then I'm with LisaLi and I'm thinking it's a bit slang as in...."hey, do I have any food on my face". "No man, you're good!"...meaning "no, you don't have any food on your face." That is how I hear it in everyday usage by native speakers.
I think that's mean /you are agood person