Does most of your traffic come from organic searches? I imagine it can be hard to rank a tool-based site that doesn't have a lot of text content
Yes, most of the visitors come from organic searches. Not necessarily, because a tool based site will be competing mostly with other tool based sites, with little or no text content. So other factors may be more important e.g bounce rate.
If you don't mind me asking, do you make money off the google ads?