diff --git a/codex-rs/core/src/context/image_generation_instructions.rs b/codex-rs/core/src/context/image_generation_instructions.rs
index 6986a7c64f25..b0c274f00f22 100644
--- a/codex-rs/core/src/context/image_generation_instructions.rs
+++ b/codex-rs/core/src/context/image_generation_instructions.rs
@@ -18,7 +18,7 @@ fn image_generation_hint(
     image_output_path: impl Display,
 ) -> String {
     format!(
-        "Generated images are saved to {image_output_dir} as {image_output_path} by default.\nIf you need to use a generated image at another path, copy it and leave the original in place unless the user explicitly asks you to delete it."
+        "Generated images are saved to {image_output_dir} as {image_output_path} by default.\nAlready displayed; do not repeat it or an unchanged copy in final Markdown unless asked.\nFor another path, copy it and keep the original unless asked to delete it."
     )
 }
 
diff --git a/codex-rs/core/tests/suite/model_switching.rs b/codex-rs/core/tests/suite/model_switching.rs
index 9ef3675b3ed2..b53ee1cba7ae 100644
--- a/codex-rs/core/tests/suite/model_switching.rs
+++ b/codex-rs/core/tests/suite/model_switching.rs
@@ -703,8 +703,11 @@ async fn generated_image_is_replayed_for_image_capable_models() -> Result<()> {
         second_request
             .message_input_texts("developer")
             .iter()
-            .any(|text| text.contains("Generated images are saved to")),
-        "second request should include the saved-path note in model-visible history"
+            .any(|text| {
+                text.contains("Generated images are saved to")
+                    && text.contains("do not repeat it or an unchanged copy")
+            }),
+        "second request should include the saved-path and render-once note in model-visible history"
     );
     let _ = std::fs::remove_file(&saved_path);
 
@@ -827,8 +830,11 @@ async fn model_change_from_generated_image_to_text_preserves_prior_generated_ima
         second_request
             .message_input_texts("developer")
             .iter()
-            .any(|text| text.contains("Generated images are saved to")),
-        "second request should include the saved-path note in model-visible history"
+            .any(|text| {
+                text.contains("Generated images are saved to")
+                    && text.contains("do not repeat it or an unchanged copy")
+            }),
+        "second request should include the saved-path and render-once note in model-visible history"
     );
     let _ = std::fs::remove_file(&saved_path);
 
diff --git a/codex-rs/ext/image-generation/src/tests.rs b/codex-rs/ext/image-generation/src/tests.rs
index 1ec9371214a4..a607ef6314f4 100644
--- a/codex-rs/ext/image-generation/src/tests.rs
+++ b/codex-rs/ext/image-generation/src/tests.rs
@@ -224,9 +224,12 @@ async fn recent_image_fallback_requires_requested_count() {
 fn generated_output_returns_image_input_and_output_hint() {
     let output_hint =
         extension_image_generation_output_hint("/tmp", "/tmp/call-1.png").expect("hint should fit");
+    let expected_output_hint = "Generated images are saved to /tmp as /tmp/call-1.png by default.
+Already displayed; do not repeat it or an unchanged copy in final Markdown unless asked.
+For another path, copy it and keep the original unless asked to delete it.";
     let output = GeneratedImageOutput {
         result: RESULT.to_string(),
-        output_hint: Some(output_hint.clone()),
+        output_hint: Some(output_hint),
     };
 
     let ResponseInputItem::FunctionCallOutput {
@@ -246,7 +249,9 @@ fn generated_output_returns_image_input_and_output_hint() {
                 image_url: format!("data:image/png;base64,{RESULT}"),
                 detail: Some(DEFAULT_IMAGE_DETAIL),
             },
-            FunctionCallOutputContentItem::InputText { text: output_hint },
+            FunctionCallOutputContentItem::InputText {
+                text: expected_output_hint.to_string(),
+            },
         ]
     );
 }