Function toMcpFailureResult

packages/hosts/mcp/src/tool-server.ts:674–701

(cause: Cause.Cause<unknown>)

});

const toMcpFailureResult = (cause: Cause.Cause<unknown>): McpToolResult => {
  const correlationId = newCorrelationId();
  const defect = Cause.findDefect(cause);
  const nativeElicitationFailed =
    Result.isSuccess(defect) &&
    Predicate.isTagged("McpNativeElicitationTransportError")(defect.success);
  // oxlint-disable-next-line executor/no-try-catch-or-throw -- boundary: best-effort defect logging must tolerate non-serializable causes
  try {
    console.error(
      `[executor:mcp] execute defect correlation_id=${correlationId}`,
      Cause.pretty(cause),
    );
  } catch {
    /* ignore logger failures */
  }
  const text = nativeElicitationFailed
    ? `Native elicitation transport failed [${correlationId}]. Reconnect the MCP client and try again.`
    : `Internal tool error [${correlationId}]`;
  return {
    content: [{ type: "text", text: `Error: ${text}` }],
    structuredContent: {
      status: "error",
      error: text,
      ...(nativeElicitationFailed ? { errorCode: "native_elicitation_transport_failed" } : {}),
    },
    isError: true,
  };
};

const recoveryText =
  "To recover, run the execute tool again with the original code; if it pauses, a fresh executionId will be issued.";