I assume, that these verbal promises are not really enforceable. Can I
make them enforceable by asking the company to put them into the
contract? How could a possible wording could look like?
Your assumption is mostly correct. Verbal agreements can be legally binding [I AM NOT A LAWYER, BUT I DO WATCH JUDGE JUDY OCCASIONALLY]. But such agreements are very, very difficult to prove [from personal experience] and thus to enforce.
Anything written into a contract can be binding and thus "enforceable".
The wording could be as simple as
- "Company agrees to give user12875 all the tools he/she needs."
- "Company agrees to provide paid travel to the conferences of user12875's choosing"
Since the phrases "all the tools needed" (who gets to determine what is "needed"? can you demand 3000 expensive tools?) and "paid travel of your choosing" (paid for what? car fare? first-class airline ticket? can you go to 100 conferences?) are very ambiguous, you would be smart to enlist the aid of a lawyer in crafting easier-to-enforce wording here.
While it's always possible to negotiate anything into a contract, I'd be shocked if any real company would actually agree to such open-ended terms.
I suspect you'd have better luck either just expecting reasonableness (and thus not writing it into the contract at all), the "local standard" (as Bill Leeper indicated in his answer), or negotiating a specific list of tools, a specific list of conferences, and the amounts you would expect the company to pay. Again, no assurances that the company would agree, but I suspect you'd have a better chance that way.
I know in my department I'm often willing to grant exceptions on an informal basis. I want to help my good team members in any way I can, but I don't want to formalize such exceptions, since they might then be expected by others.