Meeting notes or decision logs: which becomes the source of truth?

Whether teams should rely on full meeting notes or a separate decision log.

Full meeting notes preserve context, but they are often too long to use during execution. A decision log is easier to search: decision, reason, owner, rejected option, and recheck condition. The risk is that it can lose discussion nuance if the original note is not linked. For async teams, which one should be treated as the practical source of truth?