Adding meta description & keywords to the Drupal 7 head

You can use drupal_add_html_head() for adding meta description and meta keywords in header. In your theme template.php file, you can call hook_page_alter() for embeding meta. If you want to add meta description and meta keywords in your site then go to your template.php file and paste the code (display below):

function YOURTHEMENAME_page_alter($page) {
$meta_description = array(
'#type' => 'html_tag',
'#tag' => 'meta',
'#attributes' => array(
'name' => 'description',
'content' => 'some description here'
)
);
$meta_keywords = array(
'#type' => 'html_tag',
'#tag' => 'meta',
'#attributes' => array(
'name' => 'keywords',
'content' => 'some, keywords'
)
);
drupal_add_html_head( $meta_description, 'meta_description' );
drupal_add_html_head( $meta_keywords, 'meta_keywords' );
}