Hard agree. While some extremely virulent poisons might do immediate damage, their effects should be debilitating rather than damaging IMO. Paralysis (whole and/or localised) and unconsciousness should be the most common, in my opinion, but in a fantasy setting we also have the luxury of magical effects being applied by poisons; petrification, sleep, blindness (also applicable by mundane means), fear and more should also be on the table for sure.