diff --git a/config/role_registry.yaml b/config/role_registry.yaml
index a8c6eaa..806343b 100644
--- a/config/role_registry.yaml
+++ b/config/role_registry.yaml
@@ -6,12 +6,22 @@ t2:
   frontend: agents/engineering/engineering-software-architect.md
   infra:    agents/engineering/engineering-devops-automator.md
   data:     agents/engineering/engineering-data-engineer.md
+  ai:       agents/engineering/engineering-software-architect.md
+  security: agents/engineering/engineering-security-engineer.md
+  mobile:   agents/engineering/engineering-software-architect.md
   default:  agents/engineering/engineering-software-architect.md
 
 t3:
   backend:  agents/engineering/engineering-senior-developer.md
   frontend: agents/engineering/engineering-senior-developer.md
   infra:    agents/engineering/engineering-sre.md
+  data:     agents/engineering/engineering-data-engineer.md
+  ai:       agents/engineering/engineering-ai-engineer.md
+  security: agents/engineering/engineering-security-engineer.md
+  mobile:   agents/engineering/engineering-mobile-app-builder.md
+  database: agents/engineering/engineering-database-optimizer.md
+  devops:   agents/engineering/engineering-sre.md
+  docs:     agents/engineering/engineering-technical-writer.md
   default:  agents/engineering/engineering-senior-developer.md
 
 t4:
@@ -23,12 +33,18 @@ t4:
   ai:        agents/engineering/engineering-ai-engineer.md
   security:  agents/engineering/engineering-security-engineer.md
   docs:      agents/engineering/engineering-technical-writer.md
+  data:      agents/engineering/engineering-data-engineer.md
+  embedded:  agents/engineering/engineering-embedded-firmware-engineer.md
   default:   agents/engineering/engineering-senior-developer.md
 
 t5:
-  code:        agents/engineering/engineering-code-reviewer.md
-  integration: agents/testing/testing-reality-checker.md
-  api:         agents/testing/testing-api-tester.md
-  performance: agents/testing/testing-performance-benchmarker.md
-  security:    agents/engineering/engineering-security-engineer.md
-  default:     agents/engineering/engineering-code-reviewer.md
+  code:          agents/engineering/engineering-code-reviewer.md
+  integration:   agents/testing/testing-reality-checker.md
+  api:           agents/testing/testing-api-tester.md
+  performance:   agents/testing/testing-performance-benchmarker.md
+  security:      agents/engineering/engineering-security-engineer.md
+  accessibility: agents/testing/testing-accessibility-auditor.md
+  e2e:           agents/testing/testing-evidence-collector.md
+  frontend:      agents/testing/testing-accessibility-auditor.md
+  data:          agents/testing/testing-reality-checker.md
+  default:       agents/engineering/engineering-code-reviewer.md
diff --git a/core/team_runner.py b/core/team_runner.py
index 9226419..368e8d4 100644
--- a/core/team_runner.py
+++ b/core/team_runner.py
@@ -554,7 +554,9 @@ class TeamRunner:
         briefs: list[TaskBrief] = []
         for task in tasks:
             role = task.get("role", "default")
-            pref_runtime = task.get("preferred_runtime", "standard")
+            # T4 is the coding/implementation tier; default to coding_agent
+            # so implementers use Claude Code unless T3 explicitly overrides.
+            pref_runtime = task.get("preferred_runtime", "coding_agent")
             brief = parent.make_child_brief(
                 tier=4,
                 role=role,