tool
The tool element provides the Rappture GUI with information about the application being executed. The element can contain the following tags: <about></about> and <command></command>.
The about tag holds a short description introducing the application.
The command tag holds the command that should be used to start the application. There are a few special directives you can give the Rappture GUI within the command tag.

The first is the @tool directive. @tool refers to the path of the directory containing the tool.xml file. If the application (named executable in the example below) is in the same directory containing the supplied tool.xml file, @tool/executable can be used as the path of the application to be run.

The second directive is @driver. @driver refers to the name of the dynamic driver.xml file created by the Rappture GUI for the application to the read current value.

<tool>
    <about> Information about the application </about>
    <command> @tool/executable @driver </command>
</tool>