I'm glad I provoked some discussion. And you all are right that my examples weren't even specific enough.
The point is that a Next Action is the very next thing you're going to do, which needs to be an actual physical action. It has to be specific, concrete, and immediately do-able. My writing NAs look like "Write scene of Michael discussing his doubts with entertainer," not "Write for 30 minutes."
Of course, YMMV, and what matters is what works.