Function isUnknownToolCause

packages/plugins/mcp/src/sdk/invoke.ts:62–68

(cause: unknown, toolName: string)

};

const isUnknownToolCause = (cause: unknown, toolName: string): boolean =>
  // oxlint-disable-next-line executor/no-instanceof-tagged-error -- boundary: MCP SDK surfaces JSON-RPC protocol errors as this Error subclass
  cause instanceof ProtocolError &&
  (cause.code === ProtocolErrorCode.InvalidParams ||
    cause.code === ProtocolErrorCode.MethodNotFound) &&
  // oxlint-disable-next-line executor/no-unknown-error-message -- boundary: instanceof narrows to the SDK's ProtocolError, whose message carries the only unknown-tool discriminator the protocol provides
  isUnknownToolMessage(cause.message, toolName);

// ---------------------------------------------------------------------------
// Elicitation bridge — decode incoming MCP ElicitRequest, route through