diff --git a/apps/ai-game-creator-shell/src-tauri/src/ui_editor/commands/separation/model.rs b/apps/ai-game-creator-shell/src-tauri/src/ui_editor/commands/separation/model.rs
index 16b617403..985e8fda3 100644
--- a/apps/ai-game-creator-shell/src-tauri/src/ui_editor/commands/separation/model.rs
+++ b/apps/ai-game-creator-shell/src-tauri/src/ui_editor/commands/separation/model.rs
@@ -42,12 +42,8 @@ pub struct SeparationNode {
 impl SeparationNode {
     pub fn as_prompt(&self) -> String {
         format!(
-            "node_id={} area=({}, {}, {}, {}) {}",
+            "node_id={} note: {}",
             self.id.as_str(),
-            self.global_pos_x_px,
-            self.global_pos_y_px,
-            self.width_px,
-            self.height_px,
             self.note.as_prompt()
         )
     }
diff --git a/apps/ai-game-creator-shell/src-tauri/src/ui_editor/commands/separation/prompt.rs b/apps/ai-game-creator-shell/src-tauri/src/ui_editor/commands/separation/prompt.rs
index d6df93e9f..ab32085b0 100644
--- a/apps/ai-game-creator-shell/src-tauri/src/ui_editor/commands/separation/prompt.rs
+++ b/apps/ai-game-creator-shell/src-tauri/src/ui_editor/commands/separation/prompt.rs
@@ -33,7 +33,6 @@ pub(super) fn gen_extract_prompt(separation_notes: Vec<SeparationNote>) -> Strin
 pub(super) fn gen_binding_prompt(nodes: Vec<&SeparationNode>) -> String {
     let binding_system_prompt = format!(
         r#"
-  You are working under a UI elements separation workflow.
   You will be given a src UI design image and a processed image, where some ui elements are separated.
   Here were the separation requirements:
   ```
@@ -42,6 +41,10 @@ pub(super) fn gen_binding_prompt(nodes: Vec<&SeparationNode>) -> String {
   You need to recognize and review the separation using the given tool.
   field notes:
     * extracted_area MUST be the recognized area from the processed image, INSTEAD OF from the src image.
+      The processed image is the only authoritative image for extracted_area.
+      Return the pixel bounding box of the extracted element as it appears in the processed image.
+      Do not copy, infer, or reuse the source node rectangle.
+      The src image is only for identifying which semantic UI element belongs to to_node.
 
   these node need handle:
   "#
diff --git a/apps/ai-game-creator-shell/src-tauri/src/ui_editor/commands/separation/workflow.rs b/apps/ai-game-creator-shell/src-tauri/src/ui_editor/commands/separation/workflow.rs
index 1081ff2fc..2c3a629bb 100644
--- a/apps/ai-game-creator-shell/src-tauri/src/ui_editor/commands/separation/workflow.rs
+++ b/apps/ai-game-creator-shell/src-tauri/src/ui_editor/commands/separation/workflow.rs
@@ -259,6 +259,7 @@ async fn visual_binding(
             e.to_string()
         })?
         .llm;
+
     let client =
         build_game_creator_llm_client_from_llm_config(&llm_config, "llm").map_err(|e| {
             app_log!("ui_separation.error stage=visual_binding reason=build_client error={e}");
@@ -274,16 +275,23 @@ async fn visual_binding(
         schema,
     )
     .with_strict(true);
-    let base_prompt = gen_binding_prompt(nodes.to_vec());
-    let initial_history = vec![LlmMessage::user_multimodal(vec![
-        LlmMessageContentPart::InputText { text: base_prompt },
-        LlmMessageContentPart::InputImage {
-            image_url: source_url.clone(),
-        },
-        LlmMessageContentPart::InputImage {
-            image_url: processed_url.clone(),
-        },
-    ])];
+    let initial_history = vec![
+        LlmMessage::system(gen_binding_prompt(nodes.to_vec())),
+        LlmMessage::user_multimodal(vec![
+            LlmMessageContentPart::InputText {
+                text: "processed image:".to_string(),
+            },
+            LlmMessageContentPart::InputImage {
+                image_url: processed_url.clone(),
+            },
+            LlmMessageContentPart::InputText {
+                text: "src image:".to_string(),
+            },
+            LlmMessageContentPart::InputImage {
+                image_url: source_url.clone(),
+            },
+        ]),
+    ];
     let result = run_with_repair_history(
         2,
         initial_history,
@@ -518,13 +526,13 @@ pub(crate) async fn separate_ui_impl(
             for decision in &binding.decisions {
                 if let BindingDecision::Ok {
                     to_node,
-                    extracted_area: separated_image_area,
+                    extracted_area,
                 } = decision
                 {
                     let cut_path = sidecar.join(format!("cut-{}.png", to_node.as_str()));
                     match cut_processed_image(
                         processed_path.clone(),
-                        *separated_image_area,
+                        *extracted_area,
                         cut_path.clone(),
                     )
                     .await