diff --git a/calm-ai/tools/architecture-creation.md b/calm-ai/tools/architecture-creation.md
index 64ec1e4a0..f14a1c30d 100644
--- a/calm-ai/tools/architecture-creation.md
+++ b/calm-ai/tools/architecture-creation.md
@@ -38,7 +38,13 @@ Every CALM architecture MUST include:
 - [ ] Add nodes array (even if empty initially)
 - [ ] Add relationships array to connect nodes
 - [ ] Include metadata array for operational info
-- [ ] Validate against CALM schema before saving
+**🚨 MANDATORY VALIDATION (Do not skip):**
+- [ ] **Verify calm-cli is installed:** `which calm`
+- [ ] **Run CALM validation:** `calm validate -a <filename>.architecture.json`
+- [ ] **Review output for errors:** `jsonSchemaValidationOutputs`, `spectralSchemaValidationOutputs`
+- [ ] **Fix ALL errors before proceeding** - Do not assume JSON validity equals CALM validity
+- [ ] **Confirm output shows:** `"hasErrors": false, "hasWarnings": false`
+- [ ] **Document any warnings addressed**
 
 ## Best Practices