I love how so many people on the Internet are experts on a technology that has only existed for a few months 
I find the the text above reasonable, it covers all the important points and keeps to a minimal number of tokens. It guides robots how to behave, points them at our comprehensive MCP and points at a few endpoints that the agent can use to explore the site in case an MCP is off the table.
Discourse sites are kind of lucky cause LLMs already know us REALLY well. That said, they know a “picture” of us 2 years ago really well, and stuff has changed:
So even a model like sol 5.6 does not know about our MCP server, cause it is a recent years thing, same will probably go for filter endpoint.
The less advanced models may know even less.