Having stuff in writing is essential, for accountability on all sides. The exact format does not matter, neither does what passes as a signature in a company. My example was for broadest possible applicability. The point is the willingness to commit to something in writing and to take the time to reflect on the implications of doing so. If you cannot get that, you’ve already lost. There will be moving targets.

It’s interesting to see how all responses focus on the signature part as problematic due to its supposed formality. Is this an American work culture thing? I see signing off on an agreement as a signal of professional conduct and reliability.