Best way to document Array options in PHPDoc?

I'm struggling to write readable and easy to understand documentation that describes the multi-tree structure for Array options that are passed to a function.

Here is an example array structure.

$arr = [
   'fields' => [
       'title' => [
           'name'     => 'Document.title',
           'format'   => 'string',
           'readonly' => true
       ]
   ]
];

There are many possible options for the above array, but this is used as a parameter to a function that understands that structure.

function doSomething(array $arr) { ... }

I'd like to document how the array should be structured in PHPDoc, but I'm not sure what the correct approach is.

Here is what I have now.

/**
 * Holds configuration settings for each field in a model.
 * Defining the field options
 *
 * array['fields'] array Defines the feilds to be shown by scaffolding.
 * array['fields'][fieldName] array Defines the options for a field, or just enables the field if array is not applied.
 * array['fields'][fieldName]['name'] string Overrides the field name (default is the array key)
 * array['fields'][fieldName]['model'] string (optional) Overrides the model if the field is a belongsTo assoicated value.
 * array['fields'][fieldName]['width'] string Defines the width of the field for paginate views. Examples are "100px" or "auto"
 * array['fields'][fieldName]['align'] string Alignment types for paginate views (left, right, center)
 * array['fields'][fieldName]['format'] string Formatting options for paginate fields. Options include ('currency','nice','niceShort','timeAgoInWords' or a valid Date() format)
 * array['fields'][fieldName]['title'] string Changes the field name shown in views.
 * array['fields'][fieldName]['desc'] string The description shown in edit/create views.
 * array['fields'][fieldName]['readonly'] boolean True prevents users from changing the value in edit/create forms