If they are, it worked on me the first time I played - somehow it did not occur to me that a mushroom called "funeral bell" that also tells you the negative health effect was poisonous. I am generally the kind of person who will read tooltips and the handbook so that felt pretty dumb of me lol. It actually happened twice before I realized. Now I'm doing a playthrough with mods that add a bunch of mushrooms and hide the info on foods until you've tried them a few times so aside from the vanilla ones I already recognize, it is actually a gamble this time. I don't think I would want that feature in vanilla but I do like that there are poisonous mushrooms and the newly added hallucinogens. I think it adds to the idea that it's an "uncompromising" survival game and not everything in your world is friendly. You have to not only forage for food but also learn what's food and what's poison, even if that just means reading the item description.