Well, uh, that all depends.
Used to be, our jobs came with job descriptions. That is, we had specific responsibilities. Think: assembly line. If your job was installing the glovebox, that’s what you did. If someone came up to you and said, “Hey, the seatbelts are missing on this car.” You could say, “Not my job.”
Call it “specialization of labor”. Call it “obsolete”.
For years, folks in white collar office jobs have seen some variation of “and all other required duties as requested” tacked onto the end of a job description. And while the consistently shitty user experience of applying for jobs these days (despite the latest technology) suggests this is merely boilerplate for “whatever else we want, but can’t name because you wouldn’t be interested”, the simple fact remains—most job descriptions are just a start.
This is generally what you do—but you need to do other things too.
Rather than continue the employee engagement conversation ad nauseam, I feel it’s worth pointing out that coming into the organization with an eye toward solving any problems you encounter—and being willing to own things not explicitly named in the job description—is a sign of a top performer.
Applies outside the office, too, by the way.