You may buy your own tools, but the golden rule is that you don’t bring your own tools into work….unless you have a secure locker so you can protect your tools whilst not being used
Some of the chain stores I worked in, the mechanics locked up the company provided tools of their bench, because the sales staff and/or other mechanics could not be trusted to not ‘borrow’ said tools when that mechanic was not on duty
In my current store I have 30 of my own tools under lock and key, including a full suite of Di2 tools, bearing pullers and specialist hub tools