diff -u b/core/tests/Drupal/TestSite/Commands/TestSiteInstallCommand.php b/core/tests/Drupal/TestSite/Commands/TestSiteInstallCommand.php
--- b/core/tests/Drupal/TestSite/Commands/TestSiteInstallCommand.php
+++ b/core/tests/Drupal/TestSite/Commands/TestSiteInstallCommand.php
@@ -12,6 +12,7 @@
 use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Input\InputOption;
 use Symfony\Component\Console\Output\OutputInterface;
+use Symfony\Component\Console\Style\SymfonyStyle;
 
 /**
  * Command to create a test Drupal site.
@@ -64,12 +65,13 @@
   protected function configure() {
     $this->setName('install')
       ->setDescription('Creates a test Drupal site')
-      ->setHelp('The details to connect to the test site created will be returned in JSON. It will contain the database prefix and the user agent.')
+      ->setHelp('The details to connect to the test site created will be displayed upon succes. It will contain the database prefix and the user agent.')
       ->addOption('setup_class', NULL, InputOption::VALUE_OPTIONAL, 'A PHP class to setup configuration used by the test, for example, \Drupal\TestSite\TestSiteInstallTestScript')
       ->addOption('db_url', NULL, InputOption::VALUE_OPTIONAL, 'URL for database or SIMPLETEST_DB', getenv('SIMPLETEST_DB'))
       ->addOption('base_url', NULL, InputOption::VALUE_OPTIONAL, 'Base URL for site under test or SIMPLETEST_BASE_URL', getenv('SIMPLETEST_BASE_URL'))
       ->addOption('install_profile', NULL, InputOption::VALUE_OPTIONAL, 'Install profile to install the site in. Defaults to testing', 'testing')
-      ->addOption('langcode', NULL, InputOption::VALUE_OPTIONAL, 'The language to install the site in.');
+      ->addOption('langcode', NULL, InputOption::VALUE_OPTIONAL, 'The language to install the site in.')
+      ->addOption('json', NULL, InputOption::VALUE_NONE, 'Output test site connection details in JSON');
   }
 
   /**
@@ -87,10 +89,21 @@
     // Manage site fixture.
     $this->setup($input->getOption('install_profile'), $input->getOption('setup_class'), $input->getOption('langcode'));
 
-    $output->writeln(json_encode([
-      'db_prefix' => $this->databasePrefix,
-      'user_agent' => drupal_generate_test_ua($this->databasePrefix),
-    ]));
+    $user_agent = drupal_generate_test_ua($this->databasePrefix);
+    if ($input->getOption('json')) {
+      $output->writeln(json_encode([
+        'db_prefix' => $this->databasePrefix,
+        'user_agent' => $user_agent,
+      ]));
+    }
+    else {
+      $output->writeln('<info>Successfully installed a test site</info>');
+      $io = new SymfonyStyle($input, $output);
+      $io->table([], [
+        ['Database prefix', $this->databasePrefix],
+        ['User agent', $user_agent],
+      ]);
+    }
   }
 
   /**
diff -u b/core/tests/Drupal/TestSite/Commands/TestSiteTearDownCommand.php b/core/tests/Drupal/TestSite/Commands/TestSiteTearDownCommand.php
--- b/core/tests/Drupal/TestSite/Commands/TestSiteTearDownCommand.php
+++ b/core/tests/Drupal/TestSite/Commands/TestSiteTearDownCommand.php
@@ -68,6 +68,7 @@
 
     // Handle the cleanup of the test site.
     $this->tearDown($db_prefix, $db_url, $kernel->getAppRoot());
+    $output->writeln("<info>Successfully uninstalled $db_prefix test site</info>");
   }
 
   /**
diff -u b/core/tests/Drupal/TestSite/TestSiteApplication.php b/core/tests/Drupal/TestSite/TestSiteApplication.php
--- b/core/tests/Drupal/TestSite/TestSiteApplication.php
+++ b/core/tests/Drupal/TestSite/TestSiteApplication.php
@@ -31,7 +31,7 @@
    */
   public function __construct($autoloader) {
     $this->autoloader = $autoloader;
-    parent::__construct('install-test-site', '0.0.1');
+    parent::__construct('test-site', '0.0.1');
   }
 
   /**
diff -u b/core/tests/Drupal/Tests/Scripts/TestSiteApplicationTest.php b/core/tests/Drupal/Tests/Scripts/TestSiteApplicationTest.php
--- b/core/tests/Drupal/Tests/Scripts/TestSiteApplicationTest.php
+++ b/core/tests/Drupal/Tests/Scripts/TestSiteApplicationTest.php
@@ -83,8 +83,10 @@
     $phpBinaryFinder = new PhpExecutableFinder();
     $phpBinaryPath = $phpBinaryFinder->find();
 
-    $command_line = $phpBinaryPath . ' core/scripts/test-site.php install --setup_class "' . TestSiteInstallTestScript::class . '" --db_url "' . getenv('SIMPLETEST_DB') . '"';
+    // Install a site using the JSON output.
+    $command_line = $phpBinaryPath . ' core/scripts/test-site.php install --json --setup_class "' . TestSiteInstallTestScript::class . '" --db_url "' . getenv('SIMPLETEST_DB') . '"';
     $process = new Process($command_line, $this->root);
+    // Set the timeout to a value that allows debugging.
     $process->setTimeout(500);
     $process->run();
 
@@ -110,37 +112,50 @@
     $this->assertFileExists($test_file);
 
     // Install another site so we can ensure tear down only removes one site at
-    // a time.
+    // a time. Use the regular output.
+    $command_line = $phpBinaryPath . ' core/scripts/test-site.php install --setup_class "' . TestSiteInstallTestScript::class . '" --db_url "' . getenv('SIMPLETEST_DB') . '"';
+    $process = new Process($command_line, $this->root);
+    // Set the timeout to a value that allows debugging.
+    $process->setTimeout(500);
     $process->run();
-    $result = json_decode($process->getOutput(), TRUE);
-    $other_db_prefix = $result['db_prefix'];
+    $this->assertContains('Successfully installed a test site', $process->getOutput());
+    $this->assertSame(0, $process->getExitCode());
+    $regex = '/Database prefix\s+([^\s]*)/';
+    $this->assertRegExp($regex, $process->getOutput());
+    preg_match('/Database prefix\s+([^\s]*)/', $process->getOutput(), $matches);
+    $other_db_prefix = $matches[1];
     $other_key = $this->addTestDatabase($other_db_prefix);
     $this->assertGreaterThan(0, count(Database::getConnection('default', $other_key)->schema()->findTables('%')));
 
     // Now test the tear down process as well.
     $command_line = $phpBinaryPath . ' core/scripts/test-site.php tear-down ' . $db_prefix . ' --db_url "' . getenv('SIMPLETEST_DB') . '"';
     $process = new Process($command_line, $this->root);
+    // Set the timeout to a value that allows debugging.
     $process->setTimeout(500);
     $process->run();
     $this->assertSame(0, $process->getExitCode());
+    $this->assertContains("Successfully uninstalled $db_prefix test site", $process->getOutput());
 
     // Ensure that all the tables and files for this DB prefix are gone.
     $this->assertCount(0, Database::getConnection('default', $key)->schema()->findTables('%'));
     $this->assertFileNotExists($test_file);
 
-    // Ensure the other sites tables and files still exist.
+    // Ensure the other site's tables and files still exist.
     $this->assertGreaterThan(0, count(Database::getConnection('default', $other_key)->schema()->findTables('%')));
     $test_database = new TestDatabase($other_db_prefix);
     $test_file = $this->root . DIRECTORY_SEPARATOR . $test_database->getTestSitePath() . DIRECTORY_SEPARATOR . '.htkey';
     $this->assertFileExists($test_file);
 
-    // Now test the tear down process as well.
+    // Tear down the other site installed.
     $command_line = $phpBinaryPath . ' core/scripts/test-site.php tear-down ' . $other_db_prefix . ' --db_url "' . getenv('SIMPLETEST_DB') . '"';
     $process = new Process($command_line, $this->root);
+    // Set the timeout to a value that allows debugging.
     $process->setTimeout(500);
     $process->run();
     $this->assertSame(0, $process->getExitCode());
+    $this->assertContains("Successfully uninstalled $other_db_prefix test site", $process->getOutput());
 
+    // Ensure that all the tables and files for this DB prefix are gone.
     $this->assertCount(0, Database::getConnection('default', $other_key)->schema()->findTables('%'));
     $this->assertFileNotExists($test_file);
   }
@@ -152,7 +167,7 @@
     $phpBinaryFinder = new PhpExecutableFinder();
     $phpBinaryPath = $phpBinaryFinder->find();
 
-    $command_line = $phpBinaryPath . ' core/scripts/test-site.php install --langcode fr --setup_class "' . TestSiteInstallTestScript::class . '" --db_url "' . getenv('SIMPLETEST_DB') . '"';
+    $command_line = $phpBinaryPath . ' core/scripts/test-site.php install --json --langcode fr --setup_class "' . TestSiteInstallTestScript::class . '" --db_url "' . getenv('SIMPLETEST_DB') . '"';
     $process = new Process($command_line, $this->root);
     $process->setTimeout(500);
     $process->run();