The move toward action do this.
It go to the target and after stop + send event if necessary. Thats all.
If you like to use it continius (nonstop), you need to loop it as you like.
For example: after stop, in the next state you check if the target transform position is changed (so if the target moving) and go back again in to the move toward state.
But also you can use translate and and check if the distance is less than your float, it stop, and if the distance larger than your float translate the object again.