I interpret "Is it kind" as: "Will it have a desirable outcome" / "Will the listener receive this with the appropriate intention". Telling someone who made a m

I interpret "Is it kind" as: "Will it have a desirable outcome" / "Will the listener receive this with the appropriate intention". Telling someone who made a mistake: "You screwed up" may be true and necessary, but saying something such as "Let's try that again" will likely lead to a better conversation and learning opportunity.