how would i make a tool add leaderstats?

Well, You at least took the effort to do some research.. You're going to have to make use of Variables, Math, Events, Functions, and Connections.

Usually people use local scripts for tools but if we want to make an actual change to a value in leaderstats then I recommend the use of a server script.

We're going to make a tool that add 1 to a leaderstats value then the tool disappears.

-- Server Script --

-- Variables

local tool = script.Parent -- defining tool

-- Events/Connections

tool.Activated:Connect(function() -- tool "Activated" Event

    local character = tool.Parent -- defining character
    local players = game:GetService("Players") -- defining players
    local player = players:GetPlayerFromCharacter(character) -- defining player
    local leaderstats = player.leaderstats -- defining leaderstats
    local currency = leaderstats.Money -- defining currency
    local addition = 1 -- defining addition

    currency.Value = currency.Value + addition -- Adding 1 to Currency

end)

Of course.. This script may error in certain circumstances.. But that's for the better. So you can observe, problem-solve, and understand the errors.

Thanks, but did you say it deletes the tool after? Cuz like I need it to stay and then we use the points to buy other tools that give points, Thanks