I can do it pretty easily. "Nominal leftists who approve of authoritarian methods to enforce their desired political structure". That doesn't describe AnComs since, well, they're anarchic and do not approve of authoritarian methods. Generally when I see the term used, it's when the subject in question starts talking about gulags and firing lines, or otherwise imposing their flavor of "communism" on the masses by force.

If that describes you, then you're a tankie. If you were called a Russian agent, it's possible that you did something common among known Russian agents, like encouraging leftists not to vote, or otherwise act counterproductively against right wing authoritarians.

Did you do something like that?