At the end of the round those who are in the Harbour get one last placement.
Do you have to go to an empty space?
Do you get all the resources of the space you place the agent?
If you have more than one agent in the harbour do they each get to go and collect
'Yes' to all three questions.
Also, remember that you can't go back to Waterdeep Habour when reassigning Agents from the Habour.