Many of you are young, you grew to adulthood and took jobs at which you were handed things like "job descriptions". That list along with a lot of other things such as requiring employers to pay you for overtime
came to be as result in large part from the activity of unions.
The job description is like a clearly laid out set if expectations and tasks, the rules of the road at work. Should there be room to occasionally do a thing or two not listed in that job description? sure
but once that starts it's a slippery slope. Remember that "no good deed goes unpunished"
The job description exists to prevent exploitation of workers, it also benefits the employer in cases where a person is not performing their work as it provides the basis for the documentation trail via which a worker can be counseled, disciplined or fired.
When I am asked by a superior to do something that is not within my job description, I will comply quietly and not cause issue within ear shot of patients, however I will file a grivance, this is the established process thru which worker rights are protected, it is also the process via which employers look at and modify job descriptions when they need to. If you need your worker's to do more and those extra tasks involve additional skill sets, then you need to rewrite that job description and bring it to the bargaining table.