Important: Chrome will be removing support for Chrome Apps on all platforms. Chrome browser and the Chrome Web Store will continue to support extensions. Read the announcement and learn more about migrating your app.

Manifest - Description

A plain text string (no HTML or other formatting; no more than 132 characters) that describes the extension. The description should be suitable for both the browser's extension management UI and the Chrome Web Store. You can specify locale-specific strings for this field; see Internationalization for details.