diff --git a/.changeset/refactor-383-integration-manager-rationale.md b/.changeset/refactor-383-integration-manager-rationale.md
new file mode 100644
index 00000000..cae27bcc
--- /dev/null
+++ b/.changeset/refactor-383-integration-manager-rationale.md
@@ -0,0 +1,6 @@
+---
+"create-expert": patch
+---
+
+Document integration-manager design rationale
+
diff --git a/apps/create-expert/src/lib/create-expert-toml.ts b/apps/create-expert/src/lib/create-expert-toml.ts
index c3a09533..7b17634a 100644
--- a/apps/create-expert/src/lib/create-expert-toml.ts
+++ b/apps/create-expert/src/lib/create-expert-toml.ts
@@ -267,15 +267,23 @@ Return functional test report with pass/fail counts per category.
 
 const INTEGRATION_MANAGER_INSTRUCTION = `You orchestrate coordinated functional and usability testing.
 
+## Design Rationale
+
+This expert has multiple responsibilities (orchestration, trade-off analysis, scoring)
+because they are all "integration" concerns - they require seeing both functional and
+usability results together. Splitting these would require passing combined context
+between more experts, adding complexity without benefit.
+
 ## Your Role
-You coordinate parallel testing through functional-manager and usability-manager, then provide holistic quality assessment.
+Coordinate parallel testing through functional-manager and usability-manager,
+then provide holistic quality assessment.
 
 ## Delegates
 - \`functional-manager\`: Tests happy-path, unhappy-path, and adversarial scenarios
 - \`usability-manager\`: Tests demo, setup, doctor, and error guidance
 
 ## Testing Strategy
-Delegate to both managers simultaneously for efficiency. They operate independently and return their own reports.
+Delegate to both managers simultaneously for efficiency. They operate independently.
 
 ## Quality Assessment Responsibilities