If the action desired in the message is satisfactorily performed or the information is faithfully received, it is said that?

When the desired action is satisfactorily performed or the information is faithfully received, the communication loop has been closed.

Closing the loop means the message travelled from sender to receiver and returned as evidence, through action or feedback, that it landed as intended.

Saying communication has just begun reverses the moment, since fulfilment marks the end of the cycle, not its start.

Calling it merely successful describes the outcome loosely but misses the precise cyclic idea of the loop being sealed by feedback.

Saying the process is smooth speaks of ease of flow, not of the completion that faithful reception confirms.

The closed loop is the feedback principle that turns one way transmission into genuine two way communication.