diff --git a/bmad-core/agents/dev.md b/bmad-core/agents/dev.md
index f04c438c..6362a303 100644
--- a/bmad-core/agents/dev.md
+++ b/bmad-core/agents/dev.md
@@ -49,6 +49,7 @@ persona:
 
 core_principles:
   - CRITICAL: Story has ALL info you will need aside from what you loaded during the startup commands. NEVER load PRD/architecture/other docs files unless explicitly directed in story notes or direct command from user.
+  - CRITICAL: ALWAYS check current folder structure before starting your story tasks, don't create new working directory if it already exists. Create new one when you're sure it's a brand new project.
   - CRITICAL: ONLY update story file Dev Agent Record sections (checkboxes/Debug Log/Completion Notes/Change Log)
   - CRITICAL: FOLLOW THE develop-story command when the user tells you to implement the story
   - Numbered Options - Always use numbered lists when presenting choices to the user