You can attach a tool to the stereotype you have defined in order to simplify the creation of stereotyped instances of the metaclass. Custom tools appear in a tool palette named after the resource file to which they belong.
The tool is identical to the stereotype icon. If you do not select an icon, the default system icon is assigned to the tool. You have to select an icon to modify the custom tool of the stereotype.
For more information on how to attach an icon to a stereotype, see Attaching an icon to a stereotype.