diff --git a/README.md b/README.md
index 7f856a8f9..b8791f0f2 100644
--- a/README.md
+++ b/README.md
@@ -66,7 +66,7 @@ The middleware accepts an `options` Object. The following is a property referenc
 Type: `Array`  
 Default: `[ 'GET', 'HEAD' ]`
 
-This property allows a user to pass the list of HTTP request methods accepted by the server.
+This property allows a user to pass the list of HTTP request methods accepted by the middleware\*\*.
 
 ### headers
 
@@ -107,26 +107,20 @@ For more information about `publicPath`, please see [the webpack documentation](
 Type: `Boolean`  
 Default: `undefined`
 
-Instructs the module to enable or disable the server-side rendering mode. Please
-see [Server-Side Rendering](#server-side-rendering) for more information.
+Instructs the module to enable or disable the server-side rendering mode.
+Please see [Server-Side Rendering](#server-side-rendering) for more information.
 
 ### writeToDisk
 
 Type: `Boolean|Function`  
 Default: `false`
 
-If `true`, the option will instruct the module to write files to the configured
-location on disk as specified in your `webpack` config file. _Setting
-`writeToDisk: true` won't change the behavior of the `webpack-dev-middleware`,
-and bundle files accessed through the browser will still be served from memory._
-This option provides the same capabilities as the
-[`WriteFilePlugin`](https://github.com/gajus/write-file-webpack-plugin/pulls).
-
-This option also accepts a `Function` value, which can be used to filter which
-files are written to disk. The function follows the same premise as
-[`Array#filter`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter)
-in which a return value of `false` _will not_ write the file, and a return value
-of `true` _will_ write the file to disk. eg.
+If `true`, the option will instruct the module to write files to the configured location on disk as specified in your `webpack` config file.
+_Setting `writeToDisk: true` won't change the behavior of the `webpack-dev-middleware`, and bundle files accessed through the browser will still be served from memory._
+This option provides the same capabilities as the [`WriteFilePlugin`](https://github.com/gajus/write-file-webpack-plugin/pulls).
+
+This option also accepts a `Function` value, which can be used to filter which files are written to disk.
+The function follows the same premise as [`Array#filter`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter) in which a return value of `false` _will not_ write the file, and a return value of `true` _will_ write the file to disk. eg.
 
 ```js
 const webpack = require('webpack');
diff --git a/src/options.json b/src/options.json
index eeb27dd1a..f5d9a0baf 100644
--- a/src/options.json
+++ b/src/options.json
@@ -2,9 +2,11 @@
   "type": "object",
   "properties": {
     "mimeTypes": {
+      "description": "Allows a user to register custom mime types or extension mappings.",
       "type": "object"
     },
     "writeToDisk": {
+      "description": "Allows to write generated files on disk.",
       "anyOf": [
         {
           "type": "boolean"
@@ -15,30 +17,47 @@
       ]
     },
     "methods": {
+      "description": "Allows to pass the list of HTTP request methods accepted by the middleware.",
       "type": "array",
       "items": {
-        "type": "string"
+        "type": "string",
+        "minlength": "1"
       }
     },
     "headers": {
       "type": "object"
     },
     "publicPath": {
-      "type": "string"
+      "description": "The `publicPath` specifies the public URL address of the output files when referenced in a browser.",
+      "anyOf": [
+        {
+          "enum": ["auto"]
+        },
+        {
+          "type": "string"
+        },
+        {
+          "instanceof": "Function"
+        }
+      ]
     },
     "serverSideRender": {
+      "description": "Instructs the module to enable or disable the server-side rendering mode.",
       "type": "boolean"
     },
     "outputFileSystem": {
+      "description": "Set the default file system which will be used by webpack as primary destination of generated files.",
       "type": "object"
     },
     "index": {
+      "description": "Allows to serve an index of the directory.",
       "anyOf": [
         {
           "type": "boolean"
         },
         {
-          "type": "string"
+          "type": "string",
+          "minlength": "1"
         }
       ]
     }
diff --git a/test/__snapshots__/validation-options.test.js.snap b/test/__snapshots__/validation-options.test.js.snap
index e88d5b1a8..891567ffe 100644
--- a/test/__snapshots__/validation-options.test.js.snap
+++ b/test/__snapshots__/validation-options.test.js.snap
@@ -10,6 +10,7 @@ exports[`validation should throw an error on the "index" option with "{}" value
 "Invalid options object. Dev Middleware has been initialized using an options object that does not match the API schema.
  - options.index should be one of these:
    boolean | string
+   -> Allows to serve an index of the directory.
    Details:
     * options.index should be a boolean.
     * options.index should be a string."
@@ -19,6 +20,7 @@ exports[`validation should throw an error on the "index" option with "0" value 1
 "Invalid options object. Dev Middleware has been initialized using an options object that does not match the API schema.
  - options.index should be one of these:
    boolean | string
+   -> Allows to serve an index of the directory.
    Details:
     * options.index should be a boolean.
     * options.index should be a string."
@@ -27,46 +29,59 @@ exports[`validation should throw an error on the "index" option with "0" value 1
 exports[`validation should throw an error on the "methods" option with "{}" value 1`] = `
 "Invalid options object. Dev Middleware has been initialized using an options object that does not match the API schema.
  - options.methods should be an array:
-   [string, ...]"
+   [string, ...]
+   -> Allows to pass the list of HTTP request methods accepted by the middleware."
 `;
 
 exports[`validation should throw an error on the "methods" option with "true" value 1`] = `
 "Invalid options object. Dev Middleware has been initialized using an options object that does not match the API schema.
  - options.methods should be an array:
-   [string, ...]"
+   [string, ...]
+   -> Allows to pass the list of HTTP request methods accepted by the middleware."
 `;
 
 exports[`validation should throw an error on the "mimeTypes" option with "foo" value 1`] = `
 "Invalid options object. Dev Middleware has been initialized using an options object that does not match the API schema.
  - options.mimeTypes should be an object:
-   object { … }"
+   object { … }
+   -> Allows a user to register custom mime types or extension mappings."
 `;
 
 exports[`validation should throw an error on the "outputFileSystem" option with "false" value 1`] = `
 "Invalid options object. Dev Middleware has been initialized using an options object that does not match the API schema.
  - options.outputFileSystem should be an object:
-   object { … }"
+   object { … }
+   -> Set the default file system which will be used by webpack as primary destination of generated files."
 `;
 
 exports[`validation should throw an error on the "publicPath" option with "false" value 1`] = `
 "Invalid options object. Dev Middleware has been initialized using an options object that does not match the API schema.
- - options.publicPath should be a string."
+ - options.publicPath should be one of these:
+   \\"auto\\" | string | function
+   -> The \`publicPath\` specifies the public URL address of the output files when referenced in a browser.
+   Details:
+    * options.publicPath should be \\"auto\\".
+    * options.publicPath should be a string.
+    * options.publicPath should be an instance of function."
 `;
 
 exports[`validation should throw an error on the "serverSideRender" option with "0" value 1`] = `
 "Invalid options object. Dev Middleware has been initialized using an options object that does not match the API schema.
- - options.serverSideRender should be a boolean."
+ - options.serverSideRender should be a boolean.
+   -> Instructs the module to enable or disable the server-side rendering mode."
 `;
 
 exports[`validation should throw an error on the "serverSideRender" option with "foo" value 1`] = `
 "Invalid options object. Dev Middleware has been initialized using an options object that does not match the API schema.
- - options.serverSideRender should be a boolean."
+ - options.serverSideRender should be a boolean.
+   -> Instructs the module to enable or disable the server-side rendering mode."
 `;
 
 exports[`validation should throw an error on the "writeToDisk" option with "{}" value 1`] = `
 "Invalid options object. Dev Middleware has been initialized using an options object that does not match the API schema.
  - options.writeToDisk should be one of these:
    boolean | function
+   -> Allows to write generated files on disk.
    Details:
     * options.writeToDisk should be a boolean.
     * options.writeToDisk should be an instance of function."
diff --git a/test/validation-options.test.js b/test/validation-options.test.js
index 5067902f1..7a475cbe8 100644
--- a/test/validation-options.test.js
+++ b/test/validation-options.test.js
@@ -21,7 +21,14 @@ describe('validation', () => {
       failure: [true],
     },
     publicPath: {
-      success: ['/foo'],
+      success: [
+        '/foo',
+        '',
+        'auto',
+        () => {
+          return '/public/path';
+        },
+      ],
       failure: [false],
     },
     serverSideRender: {