No, that would still whipe out the content by the content pages (content in a CPH only serves as a default). I would do this:
Code:
<link href="../Styles/styles.css" rel="stylesheet" type="text/css" />
<script src="../scripts/jquery-1.7.2.min.js" type="text/javascript"></script>
<asp:ContentPlaceHolder id="head" runat="server">
</asp:ContentPlaceHolder>
This puts the CSS and JavaScript outside the CPH so it's always added to the page.
Then, in a content page, you add this to the <Content /> control for the Head CPH:
<meta name="keywords" content="" />
<meta name="description" content="" />
Hope this helps,
Imar