I would use "saccharine" or "Pollyanna" based on some of the responses I get.

Early on, ChatGPT could be tricked into being sarcastic and using many swear words. I rewrote the prompt and dialed it back a bit. It made ChatGPT have a sense of humor. It was refreshing when it stopped acting like it was reading a script like a low level technician at Comcast.