diff --git a/server/etcdmain/config.go b/server/etcdmain/config.go
index bd7ca792948..5671484ab47 100644
--- a/server/etcdmain/config.go
+++ b/server/etcdmain/config.go
@@ -201,7 +201,7 @@ func newConfig() *config {
 	fs.StringVar(&cfg.ec.DNSClusterServiceName, "discovery-srv-name", cfg.ec.DNSClusterServiceName, "Service name to query when using DNS discovery.")
 	fs.StringVar(&cfg.ec.InitialCluster, "initial-cluster", cfg.ec.InitialCluster, "Initial cluster configuration for bootstrapping.")
 	fs.StringVar(&cfg.ec.InitialClusterToken, "initial-cluster-token", cfg.ec.InitialClusterToken, "Initial cluster token for the etcd cluster during bootstrap.")
-	fs.Var(cfg.cf.clusterState, "initial-cluster-state", "Initial cluster state ('new' or 'existing').")
+	fs.Var(cfg.cf.clusterState, "initial-cluster-state", "Initial cluster state ('new' when bootstrapping a new cluster or 'existing' when adding new members to an existing cluster). After successful initialization (bootstrapping or adding), flag is ignored on restarts.")
 
 	fs.BoolVar(&cfg.ec.StrictReconfigCheck, "strict-reconfig-check", cfg.ec.StrictReconfigCheck, "Reject reconfiguration requests that would cause quorum loss.")
 
diff --git a/server/etcdmain/help.go b/server/etcdmain/help.go
index 3b4febd8aa8..6b2e11309fb 100644
--- a/server/etcdmain/help.go
+++ b/server/etcdmain/help.go
@@ -101,7 +101,8 @@ Clustering:
   --initial-cluster 'default=http://localhost:2380'
     Initial cluster configuration for bootstrapping.
   --initial-cluster-state 'new'
-    Initial cluster state ('new' or 'existing').
+    Initial cluster state ('new' when bootstrapping a new cluster or 'existing' when adding new members to an existing cluster).
+    After successful initialization (bootstrapping or adding), flag is ignored on restarts.
   --initial-cluster-token 'etcd-cluster'
     Initial cluster token for the etcd cluster during bootstrap.
     Specifying this can protect you from unintended cross-cluster interaction when running multiple clusters.