diff --git a/assets/picoclaw_detect_person.mp4 b/assets/picoclaw_detect_person.mp4
deleted file mode 100644
index b56999689..000000000
Binary files a/assets/picoclaw_detect_person.mp4 and /dev/null differ
diff --git a/assets/wechat.png b/assets/wechat.png
index e30c34e4e..1900c7556 100644
Binary files a/assets/wechat.png and b/assets/wechat.png differ
diff --git a/pkg/agent/loop.go b/pkg/agent/loop.go
index 693f2227b..7c774ff17 100644
--- a/pkg/agent/loop.go
+++ b/pkg/agent/loop.go
@@ -52,6 +52,8 @@ type processOptions struct {
 	NoHistory       bool   // If true, don't load session history (for heartbeat)
 }
 
+const defaultResponse = "I've completed processing but have no response to give. Increase `max_tool_iterations` in config.json."
+
 func NewAgentLoop(cfg *config.Config, msgBus *bus.MessageBus, provider providers.LLMProvider) *AgentLoop {
 	registry := NewAgentRegistry(cfg, provider)
 
@@ -260,7 +262,7 @@ func (al *AgentLoop) ProcessHeartbeat(ctx context.Context, content, channel, cha
 		Channel:         channel,
 		ChatID:          chatID,
 		UserMessage:     content,
-		DefaultResponse: "I've completed processing but have no response to give.",
+		DefaultResponse: defaultResponse,
 		EnableSummary:   false,
 		SendResponse:    false,
 		NoHistory:       true, // Don't load session history for heartbeat
@@ -326,7 +328,7 @@ func (al *AgentLoop) processMessage(ctx context.Context, msg bus.InboundMessage)
 		Channel:         msg.Channel,
 		ChatID:          msg.ChatID,
 		UserMessage:     msg.Content,
-		DefaultResponse: "I've completed processing but have no response to give.",
+		DefaultResponse: defaultResponse,
 		EnableSummary:   true,
 		SendResponse:    false,
 	})
diff --git a/pkg/config/config_test.go b/pkg/config/config_test.go
index bf56b7f34..45cdd8ec8 100644
--- a/pkg/config/config_test.go
+++ b/pkg/config/config_test.go
@@ -210,8 +210,8 @@ func TestDefaultConfig_WorkspacePath(t *testing.T) {
 func TestDefaultConfig_Model(t *testing.T) {
 	cfg := DefaultConfig()
 
-	if cfg.Agents.Defaults.Model == "" {
-		t.Error("Model should not be empty")
+	if cfg.Agents.Defaults.Model != "" {
+		t.Error("Model should be empty")
 	}
 }
 
@@ -331,8 +331,8 @@ func TestConfig_Complete(t *testing.T) {
 	if cfg.Agents.Defaults.Workspace == "" {
 		t.Error("Workspace should not be empty")
 	}
-	if cfg.Agents.Defaults.Model == "" {
-		t.Error("Model should not be empty")
+	if cfg.Agents.Defaults.Model != "" {
+		t.Error("Model should be empty")
 	}
 	if cfg.Agents.Defaults.Temperature != nil {
 		t.Error("Temperature should be nil when not provided")
diff --git a/pkg/config/defaults.go b/pkg/config/defaults.go
index cf799140d..8e21809ee 100644
--- a/pkg/config/defaults.go
+++ b/pkg/config/defaults.go
@@ -13,10 +13,10 @@ func DefaultConfig() *Config {
 				Workspace:           "~/.picoclaw/workspace",
 				RestrictToWorkspace: true,
 				Provider:            "",
-				Model:               "glm-4.7",
-				MaxTokens:           8192,
+				Model:               "",
+				MaxTokens:           32768,
 				Temperature:         nil, // nil means use provider default
-				MaxToolIterations:   20,
+				MaxToolIterations:   50,
 			},
 		},
 		Bindings: []AgentBinding{},
diff --git a/pkg/migrate/migrate_test.go b/pkg/migrate/migrate_test.go
index b6b3d70aa..9216442bb 100644
--- a/pkg/migrate/migrate_test.go
+++ b/pkg/migrate/migrate_test.go
@@ -296,8 +296,8 @@ func TestConvertConfig(t *testing.T) {
 		if len(warnings) != 0 {
 			t.Errorf("expected no warnings, got %v", warnings)
 		}
-		if cfg.Agents.Defaults.Model != "glm-4.7" {
-			t.Errorf("default model should be glm-4.7, got %q", cfg.Agents.Defaults.Model)
+		if cfg.Agents.Defaults.Model != "" {
+			t.Errorf("default model should be nil, got %q", cfg.Agents.Defaults.Model)
 		}
 	})
 }