Having a good/nice personality — kind, pleasant, congenial; used to describe someone's character in everyday speech.
彼女はいつも笑顔で、性格がいいから誰にでも好かれる。
She always smiles; because she has a nice personality, everyone likes her.
面接で一番印象に残ったのは、性格がいいことが伝わってきた応募者だった。
The applicant who left the strongest impression in the interview was the one whose good personality came through.
親に『性格がいい子』だと言われて育ったら、自信になることもある。
Being raised being told 'you have a good personality' by your parents can sometimes boost your confidence.