diff --git a/lib/canvas/agent-annotation-prompt.ts b/lib/canvas/agent-annotation-prompt.ts
index a98459472..f10ec02db 100644
--- a/lib/canvas/agent-annotation-prompt.ts
+++ b/lib/canvas/agent-annotation-prompt.ts
@@ -11,8 +11,20 @@ function uniqueStrings(values: Array<string | undefined | null>) {
 }
 
 export function hasCanvasAgentAnnotationEditIntent(userText: string) {
-  return /按.*(?:批注|标注|箭头|框选|备注)|(?:批注|标注|箭头|框选|圈选|annotation|note)/i.test(
-    userText
+  const text = trimText(userText, 1000);
+  if (!text) return false;
+  const annotationKeyword = "(?:批注|标注|箭头|框选|圈选|备注|annotation|note)";
+  if (new RegExp(`(?:添加|新增|创建|加|写).{0,8}${annotationKeyword}`, "i").test(text)) {
+    return false;
+  }
+  return (
+    new RegExp(`(?:按|按照|根据|依据|依照|参考|基于).{0,18}${annotationKeyword}`, "i").test(
+      text
+    ) ||
+    new RegExp(
+      `${annotationKeyword}.{0,24}(?:修改|编辑|修图|改图|处理|调整|去掉|移除|换|生成|出图|执行)`,
+      "i"
+    ).test(text)
   );
 }
 
diff --git a/tests/routes/canvas-chat-helpers.test.ts b/tests/routes/canvas-chat-helpers.test.ts
index da3030343..5bf78b524 100644
--- a/tests/routes/canvas-chat-helpers.test.ts
+++ b/tests/routes/canvas-chat-helpers.test.ts
@@ -3050,7 +3050,11 @@ test.describe("canvas chat pure helpers", () => {
     };
 
     expect(hasCanvasAgentAnnotationEditIntent("按批注修改这张图")).toBe(true);
+    expect(hasCanvasAgentAnnotationEditIntent("批注里的水印去掉")).toBe(true);
     expect(hasCanvasAgentAnnotationEditIntent("把背景换成白色")).toBe(false);
+    expect(hasCanvasAgentAnnotationEditIntent("给选中图片加批注：这里保留")).toBe(
+      false
+    );
 
     const prompt = buildCanvasAgentAnnotationEditPrompt({
       context,
@@ -3069,6 +3073,13 @@ test.describe("canvas chat pure helpers", () => {
         userText: "把背景换成白色",
       })
     ).toBe("");
+    expect(
+      buildCanvasAgentAnnotationEditPrompt({
+        context,
+        targetNodeIds: ["image-1"],
+        userText: "给选中图片加批注：这里保留",
+      })
+    ).toBe("");
   });
 
   test("labels image note action as an agent annotation entry", () => {