如何在聚合物中设置动态Meta标签和Open Graph标签？

I have a polymer node site that I've been working on and can't figure out how to include dynamic meta tags and Open Graph tags. Jquery won't work and neither will using the polymer api to add a node because it will add all the tags after the page loads and facebook won't be able to read the tags. Google crawlers do render the page but it would be best if I could set the description in the header.I have a polymer node site that I've been worki