diff --git a/README.md b/README.md
index 37b54f1..e3d7e0e 100644
--- a/README.md
+++ b/README.md
@@ -30,6 +30,7 @@ Load `docs/database-schema.md` for complete schema overview
 
 #### Testing Work
 Load `docs/testing.md` for Docker-based testing workflow
+Only use docker containers for testing. Never install local tools if they do not exist already. 
 
 ### 4. Development Environment (1 command)
 ```bash