diff --git a/toolkit/components/normandy/actions/schemas/index.js b/toolkit/components/normandy/actions/schemas/index.js
index 5ab88b395ca4..cfc4420ab404 100644
--- a/toolkit/components/normandy/actions/schemas/index.js
+++ b/toolkit/components/normandy/actions/schemas/index.js
@@ -41,28 +41,28 @@ const ActionSchemas = {
         minItems: 1,
         items: {
           type: "object",
-          required: ["slug", "value", "ratio"],
+          required: ["slug", "value", "ratio", "groups"],
           properties: {
             slug: {
               description:
-                "Unique identifier for this branch of the experiment",
+                "Unique identifier for this branch of the experiment.",
               type: "string",
               pattern: "^[A-Za-z0-9\\-_]+$",
             },
             value: {
-              description: "Message content",
+              description: "Message content.",
               type: "object",
               properties: {},
             },
             ratio: {
               description:
-                "Ratio of users who should be grouped into this branch",
+                "Ratio of users who should be grouped into this branch.",
               type: "integer",
               minimum: 1,
             },
             groups: {
               description:
-                "A list of experiment groups that can be used to exclude or select related experiments",
+                "A list of experiment groups that can be used to exclude or select related experiments. May be empty.",
               type: "array",
               items: {
                 type: "string",
diff --git a/toolkit/components/normandy/actions/schemas/package.json b/toolkit/components/normandy/actions/schemas/package.json
index 002bd6b136a0..9c7166869b54 100644
--- a/toolkit/components/normandy/actions/schemas/package.json
+++ b/toolkit/components/normandy/actions/schemas/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@mozilla/normandy-action-argument-schemas",
-  "version": "0.10.0",
+  "version": "0.10.1",
   "description": "Schemas for Normandy action arguments",
   "main": "index.js",
   "author": "Michael Cooper <mcooper@mozilla.com>",