If you want to create a tool in the palette for a profile stereotype:
- create your uml profile (you can use Papyrus to create a profile). The stereotype must extend a model element, for which there is already a tool in Papyrus.
- load the profile into the uml model, where you want to use the stereotype (select the root "Model" element in the model explorer view. rightclick on the element and load the profile).
- rightclick on the palette and choose "customize" and create the tool for the stereotype (there is a section that is called "stereotype application" or so)
You need to "apply" the profile (From the "Profile" tab in the properties view of your UML Model). "Apply" is different from "Import": To use a profile, you need to apply it. To extend a profile, you need to import it.