Use functionless root metadata to require a selected command:

// App is a command `app` -- Run jobs.
// No command: error
package commands

// Run is a subcommand `app run` -- Run a job.
func Run() { fmt.Println("run") }

Or place the same directive in native configuration:

format-version: 1
# Commands
```command: app
Description: Run jobs.
No command: error
```

The directive is an execution policy, independent of executable routing. When omitted, bare invocation preserves existing help and status 0. Only error is accepted. Empty/unknown values, duplicate declarations and policies on children are generation errors with source filename and line diagnostics. A real root action or any default route, including a help route or a child marked default, conflicts with the policy. Put it in root metadata rather than an action comment.

The dispatcher returns *cmd.UsageError unchanged, with kind cmd.UsageNoCommand, canonical root path, empty flag and nil cause. Both direct and wrapped errors support errors.Is(err, cmd.ErrUsage) and errors.As. Unknown commands and parser failures retain their distinct kinds. Generated process helpers render the error and choose default status 1 separately; wrapped explicit cmd.ErrExitCode overrides remain authoritative, including status 0. Only generated main calls os.Exit.

Explicit help, usage and version do not acquire business providers. The policy does not change selected actions, nested aliases, inherited flags, positional binding or parser-specific grammar. -- stops routing as before; without any following argument it leaves no command selected. Functionless root flags and providers still need future typed binding support under #63/#522 and are rejected rather than inferred from prose.

templates/testdata/issue524.go.txtar contains real Go/native sources, exact process invocations and help snapshots, and an inspectable empty-root golden. TestGenerateNoCommandPolicy compares equivalent Go/config output, repeats generation, compiles empty and populated applications with GNU and Go-flag, and runs direct typed-error/exit-override tests. Existing metadata scenarios also exercise ordinary root actions and default routes. No custom main, dummy action, global callbacks or runtime generator dependency is required.