How would you build SEO Tools – for testing a page’s SEO power?

What are the keys to making great SEO Tools?

I am very interested in SEO from a web development perspective.  I don’t feel the average (or even above average) web developers know enough to be good at it.  When I started my job at ClickStop, I thought I knew enough to “be dangerous”.  It turns out, I did – dangerous to my SEO.

That got me thinking – maybe I could offer some sort of test on my site to rank people’s pages, reflecting an SEO ranking…SEO Tools for Web Page Analysis.

There are a number of things that are “standard”:

  • Keyword to focus on
  • Is the keyword in the title
  • Is the keyword in the meta description
  • Does the keyword show up in the content – if so, how many times?

What things am I missing?  How would you build a service like this.

I’m thinking of building a REST service I can pass URL’s to and have it analyze the page sent…is this what you would do?  Please give me more suggestions in the comments.