The runbook that was wrong because the command changed

A runbook step naming a command that had been renamed in a refactor eight months earlier.

# the runbook said
./bin/queue-depth --by-queue

# the command is
php artisan queue:depth --group

# and the check that now runs weekly
for cmd in $(grep -ohP '^s{2,}K(./bin/S+|php artisan S+)' docs/runbooks/*.md); do
  ./bin/command-exists "$cmd" || echo "missing: $cmd"
done

A runbook is documentation that must execute correctly under pressure, which makes it closer to code than to prose — and nothing in a normal review connects a command rename to a markdown file. Extracting the commands and checking they exist is a crude test and it caught three across eight runbooks.