durable
functional
long-wearing
operable
operational
practical
usable
useable
useful
utile
advantageous
agential
agentival
agentive
aidful
aiding
appropriate
assisting
banausic
beneficial
commodious
conducive
constructive
contributory
diligent
employable
expedient
facilitating
favoring
fitting
forwarding
functioning
furthersome
good for
handy
helpful
instrumental
intermediary
long-lasting
mediating
mediatorial
ministerial
ministering
of general utility
of help
of service
of use
operating
operative
positive
practicable
pragmatical
profitable
promoting
acceptable
applicable
instructive
neat
reliable
sensible
trustworthy
unserviceable