There is a slightly longer description in the Technical Instructions section on the Rules page (https://helloworldopen.com/rules):

“The goal is to create an AI for a simple real time racing game. Your AI will sit on the drivers seat of a racing car and race against others AIs on different virtual tracks. The server will send you track details and car positions and your job is to send car control messages to the server. You'll communicate with a game server using JSON over TCP. More details will be delivered later.”