It should be possible to add a default + page specific set of meta keywords+description. Page level keywords should should be appended whereas page level description should overwrite.

<meta> Tags - Examples of Use

Define keywords for search engines:
<meta name="keywords" content="HTML, CSS, XML, XHTML, JavaScript">

Define a description of your web page:
<meta name="description" content="Free Web tutorials on HTML and CSS">

Define the author of a page:
<meta name="author" content="Matthijs Schuurman">