adding titles and summaries to social media share links

I added parameters into the links instead of using Open Graph tags (og tags) as discussed with Dak. OG tags give us more control over what displays when shared, especially in Twitter. But, this is still a big improvement over what we have now.
So I'm confused about what you mean by custom parameters, since the link provided above (https://www.facebook.com/sharer/sharer.php?u=http%3A%2F%2Fcnx.org&media=http%3A%2F%2Fcnx.org%2Flogo.png&description=CNX) seems to work with what I would call custom parameters.

The facebook developer link you provided appears to be broken.