diff --git a/tox.ini b/tox.ini
index 9bc146308..46e73e32f 100644
--- a/tox.ini
+++ b/tox.ini
@@ -144,6 +144,8 @@ passenv =
     SERVER
 
 [testenv:apacheconftest-external-with-pebble]
+# Run apacheconftest with pebble and Certbot outside of tox's virtual
+# environment.
 commands =
     {[base]pip_install} certbot-ci
     {toxinidir}/certbot-apache/tests/apache-conf-files/apache-conf-test-pebble.py --debian-modules
@@ -256,6 +258,7 @@ commands =
     coverage report --include 'certbot/*' --show-missing --fail-under=62
 
 [testenv:integration-external]
+# Run integration tests with Certbot outside of tox's virtual environment.
 commands =
     {[base]pip_install} certbot-ci
     pytest certbot-ci/certbot_integration_tests \