How to create a Tool Storage (Backpack like)?

Short answer: Yes, it's possible.

Long answer: Depending on how you actually make the interface to drop the tool into it, it could be easier or harder.

Personally, I would make a generic API that handles taking a storing the Tool, and then using the API's functions to connect the interface.

I.E.:

local toolStorage = {}
local tools = Instance.new("Folder", game.ServerStorage)
tools.Name = "Stored Tools"
local module = {}

function deepCopy(table)
    local newTab = {}
    for i, v in pairs(table) do
        if type(v) == "table" then
            newTab[i] = deepCopy(v)
        else
            newTab[i] = v
        end
    end
    return newTab
end

function module.getPlayerStorage(player)
    if not toolStorage[player] then
        return {}
    end
    return deepCopy(toolStorage[player])
end

function module.storeToolForPlayer(player, Tool)
    if not toolStorage[player] then toolStorage[player] = {} end
    table.insert(toolStorage[player], Tool)
    Tool.Parent = tools
end

function module.retrieveFromStorage(player, Tool)
    if not toolStorage[player] then error("Player does not own that Tool!") return end
    for i, v in ipairs(toolStorage[player]) do
        if v == Tool then
            table.remove(toolStorage[player], i)
            Tool.Parent = player.Backpack
            return
        end
    end
    error("Player does not own that Tool!")
end

return module

This example only works for a single storage 'container', but you could fairly easily extend it into multiple.