Enthuware

For the explanation, ejb-jar.xml is provided by the bean provider. Since he/she (bean provider) usually does not know the actual destination name, it is never specified in the ejb-jar.xml....The bean deployer uses application server specified xml files to specify that information.....

But I have seen an example in ejb-jar.xml like this in Ivan Krizan's study guide:

<assembly-description>
<message-destination>
<message-destination-name> ...
//JNDI name of the a physical queue defined in the application server.
<lookup-name>jms/ForwardingTopic</lookup-name>
</message-destination>
</assembly-description>

My notes is :
application assembler can specify actual message destination in ejb-jar.xml.

ejb-jar is provided by the bean provider. Of course, once you get the jar, you can change anything in it. Even replace or add classes but that will not be appropriate.