diff --git a/agent/agent.go b/agent/agent.go
index 10c512f5..2203e120 100644
--- a/agent/agent.go
+++ b/agent/agent.go
@@ -486,17 +486,23 @@ func (a *Agent) shouldStoreHistoryProvider(provider HistoryProvider, session *Se
 	if provider == nil {
 		return false
 	}
-	if !a.hasDefaultHistoryProvider {
-		return true
-	}
 	if a.providerDoesNotManageHistory {
 		// Provider never uses server-side history; always persist locally.
 		return true
 	}
+	if session != nil && session.ServiceID() != "" {
+		// Once the provider service owns the conversation history, no history
+		// provider should persist the run locally, even if a configured provider
+		// remains attached for future local sessions.
+		return false
+	}
+	if !a.hasDefaultHistoryProvider {
+		return true
+	}
 
 	// A provider can promote a local session to a service-managed one during the
 	// run. Once that happens, the default in-memory provider should stop storing.
-	return session != nil && session.ServiceID() == ""
+	return session != nil
 }
 
 func (a *Agent) handleHistoryProviderConflict(ctx context.Context, provider HistoryProvider, session *Session) (bool, error) {
diff --git a/agent/agent_test.go b/agent/agent_test.go
index 3c2576ff..df526090 100644
--- a/agent/agent_test.go
+++ b/agent/agent_test.go
@@ -1538,7 +1538,7 @@ func TestAgent_Run_HistoryProvider_ClearsWhenThrowDisabledAndClearEnabled(t *tes
 	}
 }
 
-func TestAgent_Run_HistoryProvider_KeepsWhenThrowAndClearDisabled(t *testing.T) {
+func TestAgent_Run_HistoryProvider_KeepsReferenceButSkipsStoreWhenThrowAndClearDisabled(t *testing.T) {
 	provideCalls := 0
 	storeCalls := 0
 	historyProvider := agent.NewHistoryProvider(agent.HistoryProviderConfig{
@@ -1575,14 +1575,14 @@ func TestAgent_Run_HistoryProvider_KeepsWhenThrowAndClearDisabled(t *testing.T)
 	if _, err := a.RunText(t.Context(), "input", agent.WithSession(agenttest.CreateSession())).Collect(); err != nil {
 		t.Fatalf("unexpected first run error: %v", err)
 	}
-	if provideCalls != 1 || storeCalls != 1 {
-		t.Fatalf("after first run provide/store = %d/%d, want 1/1", provideCalls, storeCalls)
+	if provideCalls != 1 || storeCalls != 0 {
+		t.Fatalf("after first run provide/store = %d/%d, want 1/0", provideCalls, storeCalls)
 	}
 	if _, err := a.RunText(t.Context(), "next", agent.WithSession(agenttest.CreateSession())).Collect(); err != nil {
 		t.Fatalf("unexpected second run error: %v", err)
 	}
-	if provideCalls != 2 || storeCalls != 2 {
-		t.Fatalf("after second run provide/store = %d/%d, want 2/2", provideCalls, storeCalls)
+	if provideCalls != 2 || storeCalls != 1 {
+		t.Fatalf("after second run provide/store = %d/%d, want 2/1", provideCalls, storeCalls)
 	}
 }