foolproof
inerrable
inerrant
unerring
unfailing
absolute
acceptable
agreeable
beyond all praise
certain
chaste
close
constant
correct
defectless
delicate
dependable
direct
effective
efficacious
efficient
even
exact
express
faithful
faultless
fine
flawless
handy
helpful
ideal
immaculate
impeccable
indefectible
indefective
indubitable
irreproachable
just right
mathematical
micrometrically precise
microscopic
nice
oracular
peerless
perfect
pinpoint
precise
pure
refined
reliable
infallibility
authoritative
conclusive
divine
holy
immutable
intuitive
invariable
irresistible
miraculous
prophetic
scientific
trustworthy
valid
fallible