Prove the command did what it said

A command exited 0 and printed ✓ done. You have learned that the tool reached its own success branch. You have not learned that anything happened.

This is the whole problem with verifying a CLI: the two things everybody checks are both the tool describing itself. The exit code is chosen by the same code that did the work. The output is written by it. When a tool is wrong about what it did, it is wrong on both, in agreement. That is exactly why their agreement proves nothing.

This skill needs no tools installed. It is four rules and some git.

The rule that decides everything

Evidence for a consequence must not come from the thing that performed the action.

Grade every fact before you use it: