The Agents page is provided with a sidebar placed on the left side of the web page. A sidebar in WordPress refers to a widget-ready area used by the website to display information that is not part of the main content but is displayed in a vertical column. An example of Agents page with sidebar can be found at this page.
How to manage the Agent Sidebar
In your left sidebar navigate to Appearance > Widgets and locate the Agent Sidebar box as displayed in the image below.
As you will notice, there are Available Widgets displayed in the left part of the page. On the right side you can find the Agent Sidebar where you will need to drag and drop the widgets that you want to display in the Agents page.