When asking for mbean info, through twiddle, for any MBean that is deployed as an xmbean, then attributes appear as operations, and they can be invoked as operations too.

At the same time, jmx-console shows those mbeans correctly.

For example:

X:\cvs\jboss-public\jboss-4.0\build\output\jboss-4.0.3beta\bin>twiddle info "jboss:service=JNDIView"
Description: JNDIView Service. List deployed application java:comp namespaces, the java: namespace as well as the global InitialContext JNDI namespace.
+++ Attributes:
Name: Name
Type: java.lang.String
Access: r-
Name: State
Type: int
Access: r-
Name: StateString
Type: java.lang.String
Access: r-
+++ Operations:
java.lang.String list(boolean verbose)
java.lang.String listXML()
void create()
void start()
void stop()
void destroy()
void jbossInternalLifecycle(java.lang.String method)
java.lang.String getName()
int getState()
java.lang.String getStateString()

X:\cvs\jboss-public\jboss-4.0\build\output\jboss-4.0.3beta\bin>twiddle invoke "jboss:service=JNDIView" getState
3
X:\cvs\jboss-public\jboss-4.0\build\output\jboss-4.0.3beta\bin>twiddle get "jboss:service=JNDIView" State
State=3

I remember a discussion about attributes accessed as operations, but I can't find any reference to it.