diff --git a/tests/test_apt.sh b/tests/test_apt.sh
index 04ca7dad57c5f67cc2c326d2de1f4131a2187925..bc476a3af717c9335fc746f41e52767713d73bc9 100755
--- a/tests/test_apt.sh
+++ b/tests/test_apt.sh
@@ -1,5 +1,5 @@
 #!/bin/bash
-# Check that the installation of an Ubuntu package using APT works.
+# Check that updates can be installed.
 set -e
 
 echo "Testing apt-get install"
diff --git a/tests/test_nginx_conf_valid.sh b/tests/test_nginx_conf_valid.sh
index d6b5a3fa8b26816a9f2c0f7147a0ba9ec3dd898a..b50ce14f758d92926143a976f41b51d94a267e04 100755
--- a/tests/test_nginx_conf_valid.sh
+++ b/tests/test_nginx_conf_valid.sh
@@ -1,5 +1,5 @@
 #!/bin/bash
-# Check that the Nginx configuration files are valid.
+# Checks that the webserver configuration has no errors.
 set -e
 
 if ( which nginx >/dev/null ); then
diff --git a/tests/test_nginx_status.py b/tests/test_nginx_status.py
index 882ead4173d2073bfd43a98d5ca2fa1dd9464264..d25431115177cdb19f9f12888ee3dd2921ceeb15 100755
--- a/tests/test_nginx_status.py
+++ b/tests/test_nginx_status.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 '''
-Check the Nginx status vhost response.
+Checks that the webserver is running.
 '''
 import os
 import requests
diff --git a/tests/test_nginx_vhosts.py b/tests/test_nginx_vhosts.py
index 5c7965aaee97d89fe283b829bdf4137a4ad3ee75..61bc0a4a40271cc549ad8edeee49c46bfdf9e08e 100755
--- a/tests/test_nginx_vhosts.py
+++ b/tests/test_nginx_vhosts.py
@@ -1,10 +1,7 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 '''
-This script checks for all enabled vhosts in Nginx conf that:
-* The response status code is 200 or 403.
-* The host is resolved as 127.0.0.1.
-* The Wowza response is correct on /streaming/ (only for mediaserver vhosts).
+Tests that all webserver services (vhosts) are available and reachable.
 '''
 import os
 import re
@@ -12,6 +9,12 @@ import requests
 import socket
 import sys
 
+'''
+This script checks for all enabled vhosts in Nginx conf that:
+* The response status code is 200 or 403.
+* The host is resolved as 127.0.0.1.
+* The Wowza response is correct on /streaming/ (only for mediaserver vhosts).
+'''
 
 # check that Nginx dir exists
 nginx_dir = '/etc/nginx/sites-enabled'
diff --git a/tests/test_ntp.sh b/tests/test_ntp.sh
index 14652ae3bb57c70dd2ddc8b8229ecf0474e07f78..3c91634bdcb7e94260a4a2cb2d1d36b0b4ebe43c 100755
--- a/tests/test_ntp.sh
+++ b/tests/test_ntp.sh
@@ -1,5 +1,5 @@
 #!/bin/bash
-# Check that the NTP server is reachable (date synchronization).
+# Check that the time synchronization server is reachable.
 set -e
 
 source /root/envsetup/conf.sh
diff --git a/tests/test_postfix.py b/tests/test_postfix.py
index eb825cec1e7d9bef514497d4c9801f305bbb2292..de99cc15eb8d16eb30f17e0f91405e6180f59c1d 100755
--- a/tests/test_postfix.py
+++ b/tests/test_postfix.py
@@ -1,8 +1,7 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 '''
-Check that postfix listen correctly the port 25.
-Postfix is the service which handles email sendings.
+Check that emails can be sent.
 '''
 import os
 import re
@@ -13,6 +12,7 @@ import sys
 if not os.path.exists('/etc/postfix'):
     print('Postfix dir does not exists, test skipped.')
 else:
+    # check that postfix listens the port 25 correctly
     out = subprocess.check_output('netstat -pant | grep \':25\'', shell=True)
     out = out.decode('utf-8') if out else ''
 
diff --git a/tests/test_ubicast_packages_access.py b/tests/test_ubicast_packages_access.py
index fa4e87ac3cc5c59a4d9c5607887577524f152906..5cf3b4486ef04fb79dcf767c6ce72f8689c817e7 100755
--- a/tests/test_ubicast_packages_access.py
+++ b/tests/test_ubicast_packages_access.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 '''
-Check that the skyreach server is reachable.
+Check that updates server is reachable.
 '''
 import os
 import re