How to override __lt for table comparison

[tron_thomas]

The following code attempts to override the __lt metamethod to allow comparison:

local function CompareAmounts(first, second)
    return first:GetAmount() < second:GetAmount()
end

Value =
{
    New = function(amount)
        assert(type(amount) == "number", "Invalid value amount")
       
        local self = { amount = amount }
       
        local function GetAmount()
            return self.amount
        end
       
        return
        {
           GetAmount = GetAmount,
           __lt = CompareAmounts,
        }
    end,
}

math.randomseed(os.time())

first = Value.New(math.random(100))
second = Value.New(math.random(100))

if first < second then
    print("The first value is smaller")
else
    print("The second valud is smaller")
end


However, running the program will produce a result like the following:
lua: Value.lua:29: attempt to compare two table values
stack traceback:
        Value.lua:29: in main chunk
        [C]: ?

What is needed allow for this type of comparison?