diff --git a/machines/modules/docker-stack.nix b/machines/modules/docker-stack.nix
index 2608d43..eee03ef 100644
--- a/machines/modules/docker-stack.nix
+++ b/machines/modules/docker-stack.nix
@@ -75,8 +75,7 @@ let
       networks = mkOption {
         type = types.listOf types.str;
         default = [ ];
-        description = lib.mdDoc ''
-        '';
+        description = lib.mdDoc "Networks to join.";
         example = literalExpression ''
           [
             "backend_internal"
@@ -88,24 +87,44 @@ let
       extra_hosts = mkOption {
         type = types.listOf types.str;
         default = [ ];
-        description = lib.mdDoc ''
-        '';
+        description = lib.mdDoc "Add hostname mappings.";
         example = literalExpression ''
           [
             "host.docker.internal:host-gateway"
+            "otherhost:50.31.209.229"
           ]
         '';
       };
 
       deploy = {
+        labels = {
+          default = [ ];
+          type = types.listOf types.str;
+          description = lib.mdDoc "Specify labels for the service.";
+          example = literalExpression ''
+            [
+              "com.example.description=This label will appear on the web service"
+            ]
+          '';
+        };
+
         placement = {
           constraints = mkOption {
             default = [ ];
             type = types.listOf types.str;
-            description = lib.mdDoc "";
-            example = [ "node.role==manager" ];
+            description = lib.mdDoc ''
+              You can limit the set of nodes where a task can be scheduled by defining constraint expressions.
+              Constraint expressions can either use a match (==) or exclude (!=) rule.
+              Multiple constraints find nodes that satisfy every expression (AND match).
+            '';
+            example = literalExample ''
+              [
+                "node.role==manager"
+              ];
+            '';
           };
         };
+
         update_config = {
           order = mkOption {
             default = "stop-first";
@@ -127,9 +146,12 @@ let
   networkOptions = { ... }: {
     options = with lib; {
       external = mkOption {
-        default = null;
+        default = false;
         type = types.nullOr types.bool;
-        description = lib.mdDoc "";
+        description = lib.mdDoc ''
+          If set to true, specifies that this volume has been created outside of Compose.
+          The systemd service does not attempt to create it, and raises an error if it doesn’t exist.
+        '';
         example = "true";
       };
     };