Is it possible to max inventory slots in game?

I am thinking of creating a system where players can hold up to 3 items at once in a game, here is my code so far.

local MAX_ITEMS = 3

game.Players.PlayerAdded:Connect(function(player)
    local Tools = Instance.new("IntValue",player)
    Tools.Name = "Tools"
    local backpack = player:WaitForChild("Backpack")
    backpack.ChildAdded:Connect(function(item)
        if item:IsA("Tool") then
            if Tools.Value > MAX_ITEMS then
                --Needing Help Here
                print("Too Many Items")
            else
                Tools.Value += 1
                print("ToolAdded")
            end
        end
    end)
    backpack.ChildRemoved:Connect(function(itemR)
        if itemR:IsA("Tool") then
            Tools.Value -= 1
            print("ToolRemoved")
        end
    end)
end)

Here, I need a way to not add the tool to the players backpack, but also not to mess up the Tools value, or to destroy the tool after being picked up. Anyone help?