Here are a couple of questions I consider when thinking about a role (could also be applied to a career):
1) What are the upper bounds and lower bounds of responsibility?
The goal of this question is to identify the most exciting and least exciting tasks in a given role. It's easy to think of jobs in binary terms of exciting or dull. We remember the crappy parts when we're in unfavorable moods and we anticipate the highs of a job before taking on a role full-time. Better to remember the full range of experience rather than dwell on the extremes. Another dimension to add to this question is what percentage of time is spent on the upper bounds compared to the lower bounds.
2) What are the metrics of productivity at the end of the day? What are the metrics of productivity at the end of a year?
The answers to these questions should be different. Clearly, there's just a bunch more we can get done in a full year than in one day. Another way I look at this question is to ask myself at the end of a day: "How do I know I did something and I didn't just sit on the couch?" Imagine, for example, the answers a painter might respond with. A typical answer might be that the painter spent a certain number of hours on a project. At the end of the year, the answer might be something more along the lines of how many art galleries they showed their work in.
I bring this second question up because sometimes it can be difficult to keep the long-term vision in mind when the redundancy of the day-to-day is what we see most. I'd be lying if I said a metric of productivity at the end of my day isn't making the unread number in my email inbox smaller. But knowing there's a larger goal helps me understand that every one of those emails is one of the tiny steps that when comprised together result in a much more impressive, exciting, and enlightening output.