Potent Cantrip with Toll the Dead vs Evasion

I’ve been allowing the party’s big bad enemy (a tenth-level wizard) to essentially always do damage with toll the dead. Even against the party’s monk and rogue which have Evasion. And my group is claiming I’m cheating, or reading the rules wrong in my favor. But I thought it was pretty clear. Did I make a (R.A.W.) false ruling?

Potent Cantrip: Starting at 6th level, your damaging cantrips affect even creatures that avoid the brunt of the effect. When a creature succeeds on a saving throw against your cantrip, the creature takes half the cantrip’s damage (if any) but suffers no additional effect from the cantrip.

10th level Evocation Wizard casts toll the dead, and the party’s Rogue makes her required Wisdom saving throw.

Toll the dead: You point at one creature you can see within range, and the sound of a dolorous bell fills the air around it for a moment. The target must succeed on a Wisdom saving throw or take 1d8 necrotic damage. If the target is missing any of its hit points, it instead takes 1d12 necrotic damage.

Evocation Wizard rolls out the damage and divides it in half. Then the argument starts: Our Rogue claims that since she made her save, she actually takes zero damage.

Evasion: Beginning at 7th level, you can nimbly dodge out of the way of certain area effects, such as a red dragon’s fiery breath or an Ice Storm spell. When you are subjected to an effect that allows you to make a Dexterity saving throw to take only half damage, you instead take no damage if you succeed on the saving throw, and only half damage if you fail.

But it specifically says “Dexterity saving throw” so I assumed (perhaps incorrectly) that Evasion simply would not apply in this case, as toll the dead forces a Wisdom saving throw. And made her, and the party’s monk, take half damage. Did I screw over my party?