No offense, but this is worse than useless, it's actively damaging in most cases. As an actual NDA, it's too informal. Enforcement, if any, would be a pain. A

No offense, but this is worse than useless, it's actively damaging in most cases. As an actual NDA, it's too informal. Enforcement, if any, would be a pain. As a joke between friends, it'd mostly annoy people who have lived long enough to realize friendship's occasionally fall apart in confrontational ways, and that in acrimonious separations, pieces of paper with your signature will be used against you. My answer in both cases would be the same - "We're signing a contract that gets you free advice. What does it get me?". (In the first case, both sides getting something out of it is a requirement to make it enforceable. In the second one, why am I getting useless paperwork for helping you?)