AFAIK, it is possible to mix(overwrite) annotations and deployment descriptors according to the spec.
I have a bunch of SLSB and SFSB which all are annotated. I now want to move them in a clustered environment, and so wrote a tiny tool that generates a jboss.xml file which mainly adds the

<clustered> True </clustered>

element. Unfortunately its not behaving the way I expected. Is there a document somewhere that describes the dependencies (if there are any) for/between the deployment descriptors (ejb-jar.xml, jboss.xml) and the annotations? I guess I am simply missing something, but I did not see it in the doc?s (ejb3, ejb3 tut, AS 404 doc, wiki), except the fact that some annotations cannot be overwritten. I did read on some site that the <ejb-name> needs to be defined in the ejb-jar.xml, prior before being able to use it in the jboss.xml (is this so ? do I have to do it this way ?).
I tried a couple of combinations adding or leaving out specific elements, but the app did not become available through the cluster (other apps do work clustered, but there all annotated.).

Sincerely

here a shot from the generated file:

<jboss>
 <enterprise-beans>
 <session>
 <ejb-name>AnzBBean</ejb-name>
<ejb-class>de.somewhere.medien.ejbean.AnzBBean</ejb-class>
 <clustered>true</clustered>
 <cluster-config>
 <partion-name>DefaultPartition</partion-name>
 <bean-load-balance-policy>org.jboss.ha.framework.interfaces.RoundRobin</bean-load-balance-policy>
</cluster-config>
</session>
 <session>
....