Empathy tools are physical simulations and constraint-inducing artefacts that allow designers to experience, even imperfectly, the physical or perceptual limitations their users live with. Wearing gloves to simulate reduced dexterity, viewing a screen through a blurred lens to simulate low vision, or navigating a space in a wheelchair for a day. These experiences transfer visceral understanding to a design team in ways that no amount of data can replicate. They build the kind of embodied empathy that leads to genuinely inclusive design.