Beyond covering the "why" and the problem your tool solves it's also IMO a really good idea to include a "why use this over XYZ" section if your tool happens to

Beyond covering the "why" and the problem your tool solves it's also IMO a really good idea to include a "why use this over XYZ" section if your tool happens to have a few popular alternative libraries or is similar to something that most folks in your niche already knows. Because if your tool is new, one of the first things folks are going to think is "why wouldn't I continue using XYZ?". The goal of this question isn't to put down the competition but it should draw comparisons between the tools and include the reasons why you created your tool. This could be adding certain features, doing things faster or whatever makes sense. Flask-Classful's docs https://flask-classful.teracy.org/ https://flask-classful.teracy.org/ has an excellent example of the above. The opening paragraphs cover it so well. The rest of the docs are also a good baseline example for creating useful documentation. Lots of practical code examples with very clear explanations of how it works.