I think in this day and age agents no longer need official 3P integrations, they can just use whatever API is already available (and in some cases even the UI).
(although i don't, i have a CLI)
> citation
Nope, as long as the MCP server exposes enough metadata to be cited (mostly trivial), citation is a job of the client/LLM.
> trust
Also just a function of the client. The server can't aid here at all as it's inherently untrustworthy in the system.
> measurement
Maybe. Though it's debatable how much measurement _each_ server needs, and whether that actually gives meaningful insight to optimize. This might as well be measured outside of the servers, in the client/a centralized logging system that also sees surrounding context.