Job functions should be qualified whenever possible and the desired outcome of the work should be described, rather than the method for accomplishing that outcome. For example, instead of saying, “she files folders” write that “the clerk files folders alphabetically based on category." Employers should let individuals read their job descriptions, voice any concerns, and sign their descriptions. Job descriptions should be accurate. To ensure accuracy, combine the input of many managers and employees.
The term ‘job description’ is a flexible one, but here I’ll be using it in a modern context, to describe all of the copy you’d use on an online job board. It usually includes information like job title, duties, salary, etc.