The debug parameter will generate the javafxdoc.bat (or .sh) execution script along with the options and files files that are used to generate the documentation.
<project> ... <reporting> <plugins> <plugin> <groupId>net.sf.jfxdplugin</groupId> <artifactId>maven-javafxdoc-plugin</artifactId> <version>1.0</version> <configuration> <debug>true</debug> </configuration> </plugin> </plugins> ... </reporting> ... </project>