The tool surface behind this site
Four read-only tools an agent can call while a reader has the page open, and why there are only four.
A personal site has nothing for an agent to transact. That single fact settles the whole design: every tool is read-only, and the taxonomy stops at four because a fifth would be a rephrasing of one of the first four.
The tools are not a new capability. They are the same deep module read through a different transport, which is why adding them cost one adapter and no changes to the graph.