If those were the only criteria, making friends would be easy. People have more built-in tribalism at the very least; the article reads like a '50s science fiction novel about robots making friends.
I trust you are being genuine when you say that, but what an odd comment. The article seemed like a very profound an interesting commentary on what friendship means. I fail to see any kind of science fiction in it. The article even seems to suggest friendship can cross tribal boundaries, but it takes work.
I guess trying to explain how friendship happens seems weird to me? It's obvious enough as it's happening that being forced to spend time together (as with school) generates friendships. Maybe I'm being too critical.
Is building trust and growing genuine care for someone easy for you?
Trust is always a gamble, at extreme you are putting your life on the line and you never know if the other person will decide to betray you next time regardless of what they did in the past.
Caring about someone is even harder as it is not a conscious choice we are making, it is feeling. You can't just decide from today I care about this person so they are my friend.
My point was, how do you know someone is your friend not how to make one. There is no method to make friends, at best some tips or guidelines.