Name of toolbar

When creating custom menu items I linked several , and together to get some kind of tree.
The attribute label in and indicates how it’s named in the menu.
Today I found out, that it’s possible to create own toolbar item, by simple adding the attribute toolbarPath.
Parts of my customized menu are now displayed in the toolbar as well. Works fine unless the label of the root element in the toolbar is not displayed. I simply sliced a picture and displayed the toolbar element with an icon to solve that issue. That works fine unless your switching operating systems oder themes.
My plugin.xml looks like:

        <actionSet id="odr.ActionSet">

Due to the fact that the font of every other element changes, I’m pretty sure there’s a better way of giving the root element of the tooltip a label?
any idea?