Returns a rating based on the length of the meta description

@param {number} metaDescLength the length of the meta description.

@returns {string} The rating given based on the description length.
function rateMetaDescLength( metaDescLength ) {
	var rating;

	switch ( true ) {
		case metaDescLength > 0 && metaDescLength < 120:
		case metaDescLength > maximumMetaDescriptionLength:
			rating = "ok";
			break;

		case metaDescLength >= 120 && metaDescLength <= maximumMetaDescriptionLength:
			rating = "good";
			break;

		default:
			rating = "bad";
			break;
	}

	return rating;
}