[executeTool-invalid-dictionary.https.html]
  [executeTool() rejects with TypeError when the required 'origin' dictionary member is omitted]
    expected: FAIL

  [executeTool() rejects with UnknownError for invalid JSON arguments]
    expected: FAIL

  [executeTool() rejects with UnknownError when a non-existent tool object is supplied]
    expected: FAIL