Normally I'll paste in the condition values for some of my traps, so you can decode them.
But initially I am thinking you need the snAgGblTrapMessage portion from the ${Message} - which I have not found a way to do.
I would see what your ${MessageType} shows.
Looking at the DB Manager I am wondering if any of the following would work : to return more informative data.
${OIDValue_Unicode}
${RAWValue_Unicode}
${OIDValue}
${RawValue}