Having a similar set of attributes as those in euca-describe-instances command's output is quite useful.
e.g.
euca-describe-instances
RESERVATION r-4sq6z15s myproj default
INSTANCE i-00000018 ami-00000002 192.168.0.12 192.168.0.12 running $KEYNAME ($PROJECT_NAME, $HOST) 0
or like nova-manage output:
nova-manage vm list
instance node type state launched image kernel ramdisk project user zone index
server-12 $HOST m1.small active 2011-10-12 08:54:08 2 1 $PROJECT_NAME novaadmin $ZONE 0