diff --git a/internal/agent/agent.go b/internal/agent/agent.go
index 3ec5d69441750e09c39fa7d00905765c8234da3f..674985c83fbb84ddb3d9a0df04b8705b97bf5bd4 100644
--- a/internal/agent/agent.go
+++ b/internal/agent/agent.go
@@ -521,6 +521,10 @@ func (a *sessionAgent) Run(ctx context.Context, call SessionAgentCall) (*fantasy
 }
 
 func (a *sessionAgent) scheduleCompletionNotification(sessionID, sessionTitle string) {
+	// Do not emit notifications for Agent-tool sub-sessions.
+	if a.sessions != nil && a.sessions.IsAgentToolSession(sessionID) {
+		return
+	}
 	if a.notifier == nil {
 		return
 	}