I don't mean before they become broken, because most are like that now. But a point at which they have been broken so many times that they are beyond repair.
The reason this might be a good idea is that right now there is an extremely limited market for tool, even high end one not available from vendors. Once someone buys a tool, they rarely need a new one, especially once they get a couple levels of tinker.
Perhaps this life span ONLY kicks in when a tool breaks. An example, a hoe can be broken and repaired 20 times. After that you can't fix. But if you repair it before it breaks, you can use it infinitely.
Just a thought to be the market flowing.