Does he add value to your life?

I'd say a person adds value to your relationships with others when they also encourage you to communicate more with friends/family and spend time with them in order to improve your relationships. Other things that I think add value in this case: encouraging you to make new friends (especially if they know that other than them you don't really keep in touch with others), making you more confident about yourself regarding social interaction, being happy for you when you hang out with friends/family (if that also makes you happy ofc), and simply wanting you to be happy around other people and not wanting you to depend solely on them.