Hey there,
Food poison is a rarely used mechanic. Actually poisoning someone with food is difficult, requires roleplay, unless they're the silly sort who'd eat cupcakes from a barrel. I think this sort of intrigue based trickery RP should have better feedback and support.
I recommend the following things:
Food poisons should give better feedback, with text appearing on your screen telling you the symptoms of the poison you're afflicted with as the effects take hold. Example: "You start foaming from the mouth."
Food poisons, if they have a death component shouldn't be instant. Instead, the death should be unstopable but give a timer till death with text so the person can RP suddenly falling ill and dying.
Food poison kills done by assassins should automatically tag a successful contract collection by the poisoner if they were an assassin.
Food poisons should ignore death ward (in lore, it's death spells anyways.) (it already has a counter play with neutralise poison.)
And finally, the DCs need to be way harder. You already skilled someone to get them to eat food directly. Maybe make poisoning wells diluted though, lower DCs.
Lets give our elected officials true paranoia. We can do it.
