Function tool_is_answered_by_client 

pub fn tool_is_answered_by_client(tool_name: &str) -> bool

Whether the client answers this tool call instead of server code, which is what decides that the turn suspends rather than answering the call itself.

The one place that knowledge lives, so the stored tool_kind and the engine cannot disagree. A name no client tool claims is left to the server dispatcher, which reports a hallucinated name to the LLM instead of suspending on it.