Functional Coverage of finite state machine

If the tool provide us with state and transition coverage of a finite state machine. What is functional coverage of a state machine than? What else is left for their to cover in a state machine? As tool give us the coverage of every state and state transition?

In reply to Rana Adeel Ahmad:

FSM coverage is not functional coverage. It is closer to code coverage in that can help identify what has not been tested or code that is unnecessary.

The only exception to this is if the sate of the machine is being used to communicate with another machine that is outside the design.