Constant LIST_TOOL_CLASSES 

pub const LIST_TOOL_CLASSES: &str = "Name this server's tool CLASSES — `query`, `quality`, `security`, `sandbox` — the tools in \
    each, and which are LOADED here. Call it before telling a user Roteiro cannot do \
    something: a class can be left out at startup to keep its descriptions out of every \
    turn's prompt, and `not-loaded-here` means not advertised to this session, NOT a missing \
    capability. Report the class name so the user can restart the server with it. Read-only.";

list_tool_classes — the index that keeps a withheld class discoverable.

Deliberately the shortest description here. It stands in for whole classes of prose an operator chose not to advertise, and a long stand-in would spend the saving it exists to protect: at ~90 tokens it replaces the security class’s ~819 or the sandbox class’s ~713.