diff --git a/cmd/uncloud/service/start.go b/cmd/uncloud/service/start.go
index 4a1c1121..ce1f75b3 100644
--- a/cmd/uncloud/service/start.go
+++ b/cmd/uncloud/service/start.go
@@ -19,8 +19,11 @@ func NewStartCommand(groupID string) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "start SERVICE [SERVICE...]",
 		Short: "Start one or more services.",
-		Long:  "Start one or more services.",
-		Args:  cobra.MinimumNArgs(1),
+		Long: `Start one or more previously stopped services.
+
+Starts all containers of the specified service(s) across all machines in the cluster.
+Services can be specified by name or ID.`,
+		Args: cobra.MinimumNArgs(1),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			uncli := cmd.Context().Value("cli").(*cli.CLI)
 			opts.services = args
diff --git a/cmd/uncloud/service/stop.go b/cmd/uncloud/service/stop.go
index aad49c1f..6c03fcc5 100644
--- a/cmd/uncloud/service/stop.go
+++ b/cmd/uncloud/service/stop.go
@@ -12,10 +12,9 @@ import (
 )
 
 type stopOptions struct {
-	services       []string
-	signal         string
-	timeoutChanged bool
-	timeout        int
+	services []string
+	signal   string
+	timeout  int
 }
 
 func NewStopCommand(groupID string) *cobra.Command {
@@ -23,18 +22,24 @@ func NewStopCommand(groupID string) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "stop SERVICE [SERVICE...]",
 		Short: "Stop one or more services.",
-		Long:  "Stop one or more services.",
-		Args:  cobra.MinimumNArgs(1),
+		Long: `Stop one or more running services.
+
+Gracefully stops all containers of the specified service(s) across all machines in the cluster.
+Services can be specified by name or ID. Stopped services can be restarted with 'uc start'.`,
+		Args: cobra.MinimumNArgs(1),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			uncli := cmd.Context().Value("cli").(*cli.CLI)
 			opts.services = args
-			opts.timeoutChanged = cmd.Flags().Changed("timeout")
 			return stop(cmd.Context(), uncli, opts)
 		},
 		GroupID: groupID,
 	}
-	cmd.Flags().StringVarP(&opts.signal, "signal", "s", "", "Signal to send to the container")
-	cmd.Flags().IntVarP(&opts.timeout, "timeout", "t", 0, "Seconds to wait before killing the container")
+	cmd.Flags().StringVarP(&opts.signal, "signal", "s", "",
+		"Signal to send to each container's main process.\n"+
+			"Can be a signal name (SIGTERM, SIGINT, SIGHUP, etc.) or a number. (default SIGTERM)")
+	cmd.Flags().IntVarP(&opts.timeout, "timeout", "t", 10,
+		"Seconds to wait for each container to stop gracefully before forcibly killing it with SIGKILL.\n"+
+			"Use -1 to wait indefinitely.")
 	return cmd
 }
 
@@ -46,10 +51,8 @@ func stop(ctx context.Context, uncli *cli.CLI, opts stopOptions) error {
 	defer client.Close()
 
 	stopOpts := container.StopOptions{
-		Signal: opts.signal,
-	}
-	if opts.timeoutChanged {
-		stopOpts.Timeout = &opts.timeout
+		Signal:  opts.signal,
+		Timeout: &opts.timeout,
 	}
 
 	for _, s := range opts.services {