diff --git a/flags.go b/flags.go
index d164a0a683..f3dbd18108 100644
--- a/flags.go
+++ b/flags.go
@@ -1,10 +1,12 @@
 package main
 
 import (
-	"github.com/codegangsta/cli"
+	"os"
 	"os/user"
 	"path"
 
+	"github.com/codegangsta/cli"
+
 	log "github.com/Sirupsen/logrus"
 )
 
@@ -16,6 +18,13 @@ func homepath(p string) string {
 	return path.Join(usr.HomeDir, p)
 }
 
+func getDiscovery(c *cli.Context) string {
+	if len(c.Args()) == 1 {
+		return c.Args()[0]
+	}
+	return os.Getenv("SWARM_DISCOVERY")
+}
+
 var (
 	flStore = cli.StringFlag{
 		Name:  "rootdir",
diff --git a/help.go b/help.go
new file mode 100644
index 0000000000..cf06c4ab2c
--- /dev/null
+++ b/help.go
@@ -0,0 +1,25 @@
+package main
+
+import "github.com/codegangsta/cli"
+
+func init() {
+
+	cli.CommandHelpTemplate = `{{$DISCOVERY := or (eq .Name "manage") (eq .Name "join") (eq .Name "list")}}NAME:
+   {{.Name}} - {{.Usage}}
+USAGE:
+   swarm {{.Name}}{{if .Flags}} [command options]{{end}} {{if $DISCOVERY}}[discovery]{{end}}{{if .Description}}
+DESCRIPTION:
+   {{.Description}}{{end}}{{if $DISCOVERY}}
+ARGUMENTS:
+   discovery{{printf "\t"}}discovery service to use [$SWARM_DISCOVERY]
+            {{printf "\t"}} * token://<token>
+            {{printf "\t"}} * etcd://<ip1>,<ip2>/<path>
+            {{printf "\t"}} * file://path/to/file
+            {{printf "\t"}} * zk://<ip1>,<ip2>/<path>
+            {{printf "\t"}} * <ip1>,<ip2>{{end}}{{if .Flags}}
+OPTIONS:
+   {{range .Flags}}{{.}}
+   {{end}}{{ end }}
+`
+
+}
diff --git a/join.go b/join.go
index 0a20ff3382..9446d79722 100644
--- a/join.go
+++ b/join.go
@@ -15,12 +15,12 @@ func checkAddrFormat(addr string) bool {
 }
 
 func join(c *cli.Context) {
-
-	if c.String("discovery") == "" {
-		log.Fatal("--discovery required to join a cluster")
+	dflag := getDiscovery(c)
+	if dflag == "" {
+		log.Fatal("discovery required to join a cluster. See 'swarm join --help'.")
 	}
 
-	d, err := discovery.New(c.String("discovery"), c.Int("heartbeat"))
+	d, err := discovery.New(dflag, c.Int("heartbeat"))
 	if err != nil {
 		log.Fatal(err)
 	}
diff --git a/main.go b/main.go
index 5335010a7a..16c4f21f1e 100644
--- a/main.go
+++ b/main.go
@@ -60,13 +60,13 @@ func main() {
 			Name:      "list",
 			ShortName: "l",
 			Usage:     "list nodes in a cluster",
-			Flags:     []cli.Flag{flDiscovery},
 			Action: func(c *cli.Context) {
-				if c.String("discovery") == "" {
-					log.Fatal("--discovery required to list a cluster")
+				dflag := getDiscovery(c)
+				if dflag == "" {
+					log.Fatal("discovery required to list a cluster. See 'swarm list --help'.")
 				}
 
-				d, err := discovery.New(c.String("discovery"), 0)
+				d, err := discovery.New(dflag, 0)
 				if err != nil {
 					log.Fatal(err)
 				}
@@ -85,7 +85,6 @@ func main() {
 			ShortName: "m",
 			Usage:     "manage a docker cluster",
 			Flags: []cli.Flag{
-				flDiscovery,
 				flStore,
 				flStrategy, flFilter,
 				flHosts, flHeartBeat, flOverCommit,
@@ -97,7 +96,7 @@ func main() {
 			Name:      "join",
 			ShortName: "j",
 			Usage:     "join a docker cluster",
-			Flags:     []cli.Flag{flDiscovery, flAddr, flHeartBeat},
+			Flags:     []cli.Flag{flAddr, flHeartBeat},
 			Action:    join,
 		},
 	}
diff --git a/manage.go b/manage.go
index 2c6fd39f05..b478308fc2 100644
--- a/manage.go
+++ b/manage.go
@@ -81,8 +81,9 @@ func manage(c *cli.Context) {
 	cluster := cluster.NewCluster(store, tlsConfig, c.Float64("overcommit"))
 	cluster.Events(&logHandler{})
 
-	if c.String("discovery") == "" {
-		log.Fatal("--discovery required to manage a cluster")
+	dflag := getDiscovery(c)
+	if dflag == "" {
+		log.Fatal("discovery required to manage a cluster. See 'swarm manage --help'.")
 	}
 
 	s, err := strategy.New(c.String("strategy"))
@@ -102,7 +103,7 @@ func manage(c *cli.Context) {
 
 	// get the list of nodes from the discovery service
 	go func() {
-		d, err := discovery.New(c.String("discovery"), c.Int("heartbeat"))
+		d, err := discovery.New(dflag, c.Int("heartbeat"))
 		if err != nil {
 			log.Fatal(err)
 		}