diff --git a/src/io/cloud.js b/src/io/cloud.js
index e66faf417..e8c95a15c 100644
--- a/src/io/cloud.js
+++ b/src/io/cloud.js
@@ -1,32 +1,63 @@
-/**
- * Cloud IO Device responsible for sending and receiving messages from
- * cloud provider (mananging the cloud server connection) and interacting
- * with cloud variables in the current project.
- */
-
 const Variable = require('../engine/variable');
 const log = require('../util/log');
 
 class Cloud {
+    /**
+     * @typedef updateVariable
+     * @param {string} name The name of the cloud variable to update on the server
+     * @param {(string | number)} value The value to update the cloud variable with.
+     */
+
+    /**
+     * A cloud data provider, responsible for managing the connection to the
+     * cloud data server and for posting data about cloud data activity to
+     * this IO device.
+     * @typedef {object} CloudProvider
+     * @property {updateVariable} updateVariable A function which sends a cloud variable
+     * update to the cloud data server.
+     * @property {Function} requestCloseConnection A function which closes
+     * the connection to the cloud data server.
+     */
+
+    /**
+     * Part of a cloud io data post indicating a cloud variable update.
+     * @typedef {object} VarUpdateData
+     * @property {string} name The name of the variable to update
+     * @property {(number | string)} value The scalar value to update the variable with
+     */
+
+    /**
+     * A cloud io data post message.
+     * @typedef {object} CloudIOData
+     * @property {VarUpdateData} varUpdate A {@link VarUpdateData} message indicating
+     * a cloud variable update
+     */
+
+
+    /**
+     * Cloud IO Device responsible for sending and receiving messages from
+     * cloud provider (mananging the cloud server connection) and interacting
+     * with cloud variables in the current project.
+     */
     constructor () {
         /**
          * Reference to the cloud data provider, responsible for mananging
          * the web socket connection to the cloud data server.
-         * @type{!object}
+         * @type {?CloudProvider}
          */
         this.provider = null;
 
         /**
          * Reference to the stage target which owns the cloud variables
          * in the project.
-         * @type{!Target}
+         * @type {?Target}
          */
         this.stage = null;
     }
 
     /**
      * Set a reference to the cloud data provider.
-     * @param {object} provider The cloud data provider
+     * @param {CloudProvider} provider The cloud data provider
      */
     setProvider (provider) {
         this.provider = provider;
@@ -43,7 +74,7 @@ class Cloud {
 
     /**
      * Handle incoming data to this io device.
-     * @param {object} data The data to process
+     * @param {CloudIOData} data The {@link CloudIOData} object to process
      */
     postData (data) {
         if (data.varUpdate) {
@@ -66,8 +97,8 @@ class Cloud {
     /**
      * Update a cloud variable in the runtime based on the message received
      * from the cloud provider.
-     * @param {object} varUpdate Data describing a cloud variable update received
-     * from the cloud data provider.
+     * @param {VarUpdateData} varUpdate A {@link VarUpdateData} object describing
+     * a cloud variable update received from the cloud data provider.
      */
     updateCloudVariable (varUpdate) {
         const varName = varUpdate.name;