Before Writing Tools: 50 Essential Strategies for Every Writer became an actual book, the tools were a series of blog posts Roy Peter Clark wrote over at Poynter.org. The version I’ve read were those original 50 blog posts collected in PDF form. You can find all the original collected posts here and if you want to you can download the PDF from my Dropbox folder here.
From what you can see on the actual book’s table of contents there are some differences from the the names of the tools and how it’s divided by parts, but it’s still the same basic 50 tips. It takes you from the basics of grammar, to the more advance story telling techniques like “saving string” and “foreshadowing”. It’s a writing exercise book. Every tool ends with a “Workbench” section which are a series of suggestions to practice what you just learned.
I highly recommend it if you want to improve your writing. Here’s a great review from Snarkmarket if you still need more convincing.