✓ Accepted answer
You're finding the tool, but you're not doing anything with it. The while loop doesn't know what the variable v is, because it is defined locally in the for loop. Just use the code in the for loop instead.
plr = game.Players.LocalPlayer
repeat wait() until plr.Character
for _,v in pairs(plr.Character:GetChildren()) do
if v:IsA("Tool") then
v:Destroy()
end
end
If you do want to find v outside of the loop, then you only need to make a variable for it.
plr = game.Players.LocalPlayer
local tool;
repeat wait() until plr.Character
for _,v in pairs(plr.Character:GetChildren()) do
if v:IsA("Tool") then
tool = v
end
end
while wait(1) do
if tool then
v:Destroy()
end
end