Function is_tool_visible 

pub fn is_tool_visible(
    name: &str,
    profile: &ToolProfile,
    disabled: &[String],
    quirks: ClientQuirks,
    role_allows: bool,
) -> bool

Decides whether a tool name should appear in tools/list.

role_allows is supplied by the caller (it depends on the active role, which is resolved outside this pure function). Internal tools are hidden unconditionally — they’re invoked automatically or via INVOKER.