diff --git a/internal/agent/agent.go b/internal/agent/agent.go
index 85394f17728ca4d01088bbcb2eff16e3136ffd55..7fdc0641fb282b4478d5c5a142c7f4241bb49514 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
 	}