Rationale
Two workers editing one file, and forty worktrees producing thousands of concurrently modified files, are the failures a declared scope prevents. The scope is a contract other workers can read and a boundary a command can check.
Required behaviour
Claim the paths a task needs when it starts; if the fix is elsewhere, stop and record it rather than widening the scope silently.
Failure behaviour
Nothing decides this rule directly, so a violation is reported by nobody; it is the rules that depend on it that decide what a machine can decide and stop or warn accordingly.
Verification
The enforced rules whose depends_on names this one carry the validators, the tests and the CI wiring. majordomus doctrine list shows them.