SEO and Django with title and description tags

Question

I have a base.html for the base template for my files. I have a tag inside it where I define both title & description tags.
I also have my home page that is home.html and it doesn't need a specific title or description a general one is enough .
I also have detail.html used for blog posts and I try to improve the seo with this

 :<meta name="description"
 content="{{ blog.formatted_summary|striptags }}">

<title>{{ blog.title|safe }}</title>

I am  defining both title and description twice and I can't think why that would be a good idea. How do I insert the title and description into the base.html so if it is a blog post that I can specify to take the body or the summary as a description without defining the properties again?