Reading through the documentation, I get a sense that the "agent" server could be any application that exposes an agent card and follows the protocol. Doesn't really have to be using LLM or be "agentic" (guess that's where the agent black box) comes in.
There isn't really much more to it than I already wrote. It's minimal, local, markdown-based, and terminal-friendly. There is some basic customizability (special files to add a footer and/or a header), and that's it.
If you already have SSH set up (e.g. for GitHub), it really just takes a minute to get started, so I'd just give it a try and see whether this is the right thing for you.