cli: make bundled help self-describing

packages/inbox-runtime/internal/cli/inbox/show.go

@@ -20,6 +20,14 @@ func newShowCmd(root *rootOptions) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "show",
 		Short: "Show one thread with message history",
+		Long: helpLong(
+			"Use show to inspect one thread together with its message history.",
+			"Workers should usually inspect the assigned thread before making assumptions about task body, payload JSON, or prior coordination.",
+			"Leaders can also use show for manual debugging and repair.",
+			"Use show when you need the exact message sequence inside one thread, not just a filtered thread list.",
+		),
+		Example: `  inbox --db .agents/coord.db show --thread thr_123
+  inbox --db .agents/coord.db --agent worker-a show --thread thr_123 --mark-read`,
 		RunE: func(cmd *cobra.Command, args []string) error {
 			ctx := cmd.Context()
 
@@ -71,7 +79,7 @@ func newShowCmd(root *rootOptions) *cobra.Command {
 	}
 
 	cmd.Flags().StringVar(&opts.threadID, "thread", "", "Thread ID")
-	cmd.Flags().BoolVar(&opts.markRead, "mark-read", false, "Advance the caller's read cursor to the latest message")
+	cmd.Flags().BoolVar(&opts.markRead, "mark-read", false, "Advance the caller's read cursor to the latest message in this thread")
 	_ = cmd.MarkFlagRequired("thread")
 
 	return cmd