Writing job descriptions

Some tips from HR works:

It should be an accurate, realistic and current picture of what is done or what is expected of the job incumbent.
It outlines the job’s location in the organisation, job purpose and content, the relationships involved, authority, controls and checks.
The incumbent and the supervisor must understand it equally well and must interpret it in the same way.
It must be able to be used as a selection tool and an interview guide when recruiting new staff.
It must be a guide for the incumbent and supervisor in establishing job objectives, standards of performance and assessing performance.
The job tasks must be listed in order of importance or in a logical sequence. Each task must state WHAT and HOW with enough detail to explain the HOW of the job i.e. IT MUST BE MEASURABLE.