cli: improve job and status text (#18628)

command/job_status.go

@@ -30,7 +30,7 @@ type JobStatusCommand struct {
 
 func (c *JobStatusCommand) Help() string {
 	helpText := `
-Usage: nomad status [options] <job>
+Usage: nomad job status [options] <job>
 
   Display status information about a job. If no job ID is given, a list of all
   known jobs will be displayed.

command/status.go

@@ -27,6 +27,9 @@ Usage: nomad status [options] <identifier>
   detect the type of resource being queried and display the appropriate
   status output.
 
+  If no arguments are provided, the command will fallback to "nomad job status",
+  which will list all jobs.
+
 General Options:
 
   ` + generalOptionsUsage(usageOptsDefault) + `