In a nutshell the following
Job title: One that everyone understands and represents the role and seniority
Department: Which department the role is in
Reports to: Who the role reports to
Responsible for: This can be roles or departments
Grade: If you have grades within you company remember these need to be clearly defined.
Overall Purpose: Summarise what the role
Key Accountable areas: This is where you document what is required for the role. As mentioned before, you don’t want to document a process, but identify what this role is responsible for and group into areas of their role.
You can of course put in the job description requirements of the job i.e. qualifications, sign off levels, travel requirements etc, but you want to finish this process and not make it look like a job specification which you would use for advertising the role.