When you sign a contract, things are going right. You and the other party are friends, everyone loves each other, etc. The day you sign the contract, you don't need it. The temptation to not worry about it is huge.
But the day you need the contract, you'll wish you had worried about it.
I disagree. Contracts are there to make sure that minds meet in as clear a fashion as possible, hopefully preventing things from going wrong. Contracts are often totally inadequate when things do actually go wrong.
I think you're both right (parent + grandparent). Contracts are where both parties hammer out the exact nature of the relationship. Responsibilities, compensation, duties, etc. with the goal being everyone having a clear understanding of how things will work. That being said, when/if things go bad, the contract then becomes the document you use to guide the resolution if it relates to employment. For instance "my manager ordered me to work X hours of unpaid overtime or be fired when my contract says any overtime work means 1.5x base compensation." Silly example, but the contract gives the employee (or the employer if the employee does something incredibly stupid) some measure of legal protection and recourse including suing the other party.
In the instance of the Skype people, if they weren't given the MPA document and the clawback clause explicitly refers to policies in that document as the basis for clawback, then I think they have a case for fraud on the grounds of dishonesty (disclaimer: IANAL) and at a minimum have skype refund them all the taxes they paid (if any) on the stock options.
Contracts exist for when things go wrong.
When you sign a contract, things are going right. You and the other party are friends, everyone loves each other, etc. The day you sign the contract, you don't need it. The temptation to not worry about it is huge.
But the day you need the contract, you'll wish you had worried about it.