TDD is my best Swagger

I know about Swagger but I am not using it on my current user. I say that TDD is my best swagger.

I worked with similar technologies on another projects. This is very useful tool for development. But for this case when I am a single developer on the project. It is overhead. If I have a small team I will not use swagger because the current solution is enough. So what is Swagger.

The goal of Swagger™ is to define a standard, language-agnostic interface to REST APIs which allows both humans and computers to discover and understand the capabilities of the service without access to source code, documentation, or through network traffic inspection. When properly defined via Swagger, a consumer can understand and interact with the remote service with a minimal amount of implementation logic. Similar to what interfaces have done for lower-level programming, Swagger removes the guesswork in calling the service.

The description is from NPM.
So I start using Swagger when I have a big team that is divided into Front and back teams to loose coupling or when I will prepare the project for outsource to make deliverable processes stricter or in another cases.