Which tools this account should not be shown

About 42 of the MCP tools only make sense if you own the product behind them — VPS power controls with no VPS can only ever answer "not found". The hosted MCP server filters those out of tools/list; this endpoint is how a client that keeps its own tool catalogue (the local stdio server) does the same.

It returns the answer, not the rules: a list of tool names to hide. A client holding a copy of the prefix-to-family logic would drift the first time a family is added, and would need a release to catch up.

hidden rather than visible, deliberately: a client that cannot reach this hides nothing and serves its whole catalogue. Too many tools is recoverable; too few silently removes capability you pay for.

The purchase path is never in this list. An account that owns nothing is exactly the account that needs to buy something, and an agent cannot ask for a tool it cannot see.

known is false when ownership could not be determined — treat it as "hide nothing", never as "owns nothing".