The issue with this is it still emphasizes assessing others, which is narcissistic in itself. I think a better test is self-analysis, do I make room for others when I speak, when I listen, even and especially when the spotlight is on me?
One of the most effective ways to determine the degree of another's narcissism is to reflect on how you feel in their company. If you feel genuinely heard, respected & valued (if they're able take a deep interest in you), it's unlikely they have high narcissistic tendencies...1/2