Attempt to index number with value on size changing?

I have a custom starter character and wanted it so if you touch an object, it changes sizes. I noticed there was no bodyscale properties in the regular Humanoid, so I added a humanoid description, but trying to change the scale shows an error. I've seen an error like this before, but can't get a good solution for it since I want the size to be a set size of 0.75. The code is here:

local debounce = false

script.Parent.Touched:Connect(function(hit)
	local humparent = hit.Parent:FindFirstChild("Humanoid")
	if humparent then
		local hum = humparent:FindFirstChild("HumanoidDescription")
		if hum then
			debounce = true
			hum.WidthScale.Value = 0.75
			hum.DepthScale.Value = 0.75
			hum.HeightScale.Value = 0.75
			wait(1)
			debounce = false
		end
	end
end)