Explanation of what this project does is not clear

[rjmunro]

The README states "Adds support for JSON Schema in Atom." but that doesn't really say what it does.

I'd expect that to mean that it helps you write JSON schemas for your JSON files - things like specific syntax highlighting for writing JSON Schemas, ways to test some existing files against the schema you are writing, maybe tools to extract sub-schemas to references etc.

It doesn't really provide tools for working with JSON schemas, except in as much as there is a schema for them at http://schemastore.org/, which you can use.

I think a better description is "Provides validation and autocompletion for many JSON based file formats, based on the schemas at http://schemastore.org/json/".