The administrative role differs from one company to the other. What do you think should be the Job description of an Administrative role?

Actually, the job description of any role is not fixed, it is designed according to business needs and is actually individualised.
The job description is a documentation of the your job design, although it is not fully reflecting the job design yet it can point your responsibilities, skills your reporting and how you can be developed latter.
That is why it is very important to document all employees job descriptions not only the administrators.
Many organisations are using the job description just to highlight the duties yet actually it is much more than that.

Must include the job description the basic functions of management are then determine functions of the company in detail where the widening tasks manager and is determined based on the sector in which they operate the company in addition to the size of its business and number of employees and the surrounding circumstances in addition to that determined by job descriptions based on the company's policies and philosophysuch as centralized management of delegated authority ....

An administration role might be:- “To provide full personal assistant and administrative support to the management team” for specific Finance administration role might be:- “Responsible for the accurate day to day financial management of a number of School accounts, involving the preparation and monitoring of budgets, and investigation of variances” but (in general) the shared part in an administration role that She/he should be able to motivate people and make them feel that they are an important cog in the business wheel.
Do his best to make life for everyone in the company as profitable, productive and enjoyable as possible he is one who does the planning, co-ordinating and organising of activities to reach the required goals.

Trying make others' job easier by guiding and motivating them in the direction of established goals by clarifying role and task requirements and to inspire them to transcend their own self-interests for the good of organization and be capable of having a profound and extraordinary effect on them.

أصف دور العمل الإداري بمثابة النواة لأي شركة ففيه توجد شيفرة النجاح و القابلية للتطور أو العكس