A really fast thesaurus... with lots of synonyms.
Positive words to describe someone include kind, compassionate, diligent, confident, intelligent, and charming — choose the trait that best captures their character.
It depends on the trait: choose compassionate or generous for warmth, diligent or driven for work ethic, astute or insightful for intelligence, and charismatic or affable for likeability.
Pick the single trait that stands out most — kind, dependable, confident, or witty — rather than a general word like "nice", which tells the reader very little.