What is the ruling on an employee remaining in his job without performing any notable tasks, and is his accountability thus absolved?

If you did not stipulate a specific place of work when contracting with the state, then they have the right to transfer you, unless it causes you unbearable harm. You must fulfill the work contract as long as you do not suffer harm, and it is sufficient for you to exert your effort during work hours; so, if a task is assigned to you, you are obliged to perform it, and if nothing is assigned to you, there is no blame upon you.