What it takes to say YES and what it means to say SO...

YES - Indicates an affirmative response...
AFFIRMATIVE - Expressing or manifesting praise or approval
APPROVAL - Acceptance as satisfactory
ACCEPTANCE - The act of taking something that is offered
SATISFACTORY - Meeting requirements
REQUIREMENTS - Needs

It is so easy to say YES - but the question is that, is YES given as an answer just a simply way of ending a conversation, an argument, a request, a demand, a question, a statement...

What if YES given today or minutes ago suddenly turns out to be a "NO". Then again you'd get an affirmative answer, that is, YES. Word uttered as it is but the ACTION is the other way around.

What does it take to say YES such that the outcome is as required?

...such is for somebody who so easily says so but does the opposite