Indicates if it is a delay loading command. By default, the assemblies associated with Add-In buttons and tools are not loaded until the corresponding item on a toolbar or menu is clicked by the user. This behavior helps conserve application memory and other resources. Since the enabled state of an Add-In button or tool is controlled by the OnUpdate method within code, they will initially appear enabled. If you need tighter control over the initial enabled state of a button or tool, you will need to override the default behavior and force the item to load at startup by setting the attribute equal to false.

Namespace: http://schemas.esri.com/Desktop/AddInsSchema: DesktopAddIns_ElementOnly.xsd

<xs:attribute default="true" name="onDemand" type="xs:boolean" use="optional" xmlns:xs="http://www.w3.org/2001/XMLSchema"></xs:attribute>