How can I use Clay to find leads that need a new website?

Hey Folks, How would you use Clay to indentify and categorise leads to if they have a good or a bad website? We have an Webdesign Client and want to filter a list of Leads so we only contact leads that would need a new website. Not sure which point to look at and which tools to use. So does anyone of you ever built a Clay Table like this and could share their experience if its possible or not? I am excited to get your ideas!