description字数显示问题

[lx9912]

我已经将classes/Product.php数字改为

protected $fieldsSizeLang = array('meta_description' => 800, 'meta_keywords' => 800,
       'meta_title' => 500, 'link_rewrite' => 500, 'name' => 500, 'available_now' => 800, 'available_later' => 800);

但是页面显示还是只有256个字符，请问如何解决。版本是是1.25

<meta name="description" content="Philips Lighting markets and manufactures more than 3,000 lighting products to retail, industrial/commercial, consumer and OEM markets around the World. Featured products include the Earthlight, Alto, MasterColor, Arena Vision and Halogena families. The P" />

，还有首页显示的description，keywords，如果更改显示。

产品删除后能否自动删除产品图片。