I got NPE on jboss startup:

at org.jboss.as.server.deployment.DeploymentUnitPhaseService.start(DeploymentUnitPhaseService.java:119) [jboss-as-server-7.1.1.Final.jar:7.1.1.Final]
at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1811) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1746) [jboss-msc-1.0.2.GA.jar:1.0.2.GA]
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895) [rt.jar:1.6.0_45]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918) [rt.jar:1.6.0_45]
at java.lang.Thread.run(Thread.java:662) [rt.jar:1.6.0_45]
Caused by: java.lang.NullPointerException
at org.jboss.as.ejb3.deployment.processors.annotation.PoolAnnotationInformationFactory.fromAnnotation(PoolAnnotationInformationFactory.java:43)
at org.jboss.as.ejb3.deployment.processors.annotation.PoolAnnotationInformationFactory.fromAnnotation(PoolAnnotationInformationFactory.java:35)
at org.jboss.as.ee.metadata.ClassAnnotationInformationFactory.createAnnotationInformation(ClassAnnotationInformationFactory.java:127)
at org.jboss.as.ee.metadata.AbstractEEAnnotationProcessor.deploy(AbstractEEAnnotationProcessor.java:54)
at org.jboss.as.server.deployment.DeploymentUnitPhaseService.start(DeploymentUnitPhaseService.java:113) [jboss-as-server-7.1.1.Final.jar:7.1.1.Final]
... 5 more

Root cause is empty value for Pool annotation in my code. I think it would be better to generate more informative exception message in this place.