diff --git a/crates/hook/src/hook.rs b/crates/hook/src/hook.rs
index 826ec3a0e..e3b0b6e9c 100644
--- a/crates/hook/src/hook.rs
+++ b/crates/hook/src/hook.rs
@@ -756,26 +756,42 @@ pub fn run_stop_hook(rt: &Runtime, stdin: &str) -> RunResult {
         );
     }
     let short = footer_mode_short(&mut cache, &session_id);
-    let attribution_note = if unknown > 0 {
+    let mut attribution_note = if fresh_groups.iter().any(|group| {
+        group.findings.iter().any(|f| f.name.starts_with("[attribution unknown]"))
+    }) {
         format!("{ENVELOPE_PREFIX} {}", stop_baseline::UNKNOWN_NOTE)
     } else {
         String::new()
     };
-    let reserve = design_note_reserve(rt, &scan, &mut cache, &session_id)
-        + if attribution_note.is_empty() { 0.0 } else { (utf16_len(&attribution_note) + 2) as f64 };
-    let rendered = render_grouped_template(
+    // Findings and attribution take priority. Append the lower-priority stale
+    // DESIGN.md notice only if it fits, without consuming its session flag.
+    let render = |note: &str| render_grouped_template(
         rt,
         &fresh_groups,
         &config,
         &RenderOpts {
             cwd: Some(project_cwd.clone()),
             short_footer: short,
-            reserve_chars: reserve,
+            reserve_chars: if note.is_empty() { 0.0 } else { (utf16_len(note) + 2) as f64 },
         },
     );
+    let mut rendered = render(&attribution_note);
+    if !attribution_note.is_empty() && !rendered.lines().any(|line| {
+        line.starts_with("- ") && (line.contains("[attribution unknown]") || line.contains("[new]"))
+    }) {
+        // At the minimum budget, a grouped header and policy footer may crowd
+        // out even the first finding. Shorten the notice before losing it.
+        attribution_note = format!("{ENVELOPE_PREFIX} {}", stop_baseline::COMPACT_UNKNOWN_NOTE);
+        rendered = render(&attribution_note);
+    }
+    // maxFindings / maxChars may also remove all unknown findings. Do not
+    // attach their guidance to an output that only shows confirmed new debt.
+    let shows_unknown = rendered.lines().any(|line| {
+        line.starts_with("- ") && line.contains("[attribution unknown]")
+    });
+    let text = if shows_unknown { format!("{attribution_note}\n\n{rendered}") } else { rendered };
     let text =
-        append_design_system_note_once(rt, &rendered, &scan, &mut cache, &session_id, &config);
-    let text = if attribution_note.is_empty() { text } else { format!("{attribution_note}\n\n{text}") };
+        append_design_system_note_once(rt, &text, &scan, &mut cache, &session_id, &config);
     commit_footer_shown(rt, &mut cache, &session_id, &text);
     persist_cache(rt, &project_cwd, &cache);
     let all: usize = fresh_groups.iter().map(|g| g.findings.len()).sum();
diff --git a/crates/hook/src/stop_baseline.rs b/crates/hook/src/stop_baseline.rs
index 36ec78df0..bd5d31b15 100644
--- a/crates/hook/src/stop_baseline.rs
+++ b/crates/hook/src/stop_baseline.rs
@@ -15,6 +15,7 @@ const FIELD: &str = "stopBaseline";
 const MAX_BYTES: usize = 512 * 1024;
 const MAX_FINDINGS: usize = 256;
 pub const UNKNOWN_NOTE: &str = "Findings marked attribution unknown may predate this session; do not treat them as regressions or broaden the task without asking.";
+pub const COMPACT_UNKNOWN_NOTE: &str = "Unknown findings may predate this session; ask before expanding scope.";
 
 fn independent(finding: &Finding) -> bool {
     !finding.antipattern.starts_with("design-system-")
diff --git a/crates/hook/tests/hook_tests.rs b/crates/hook/tests/hook_tests.rs
index 268d27e77..f086b60d4 100644
--- a/crates/hook/tests/hook_tests.rs
+++ b/crates/hook/tests/hook_tests.rs
@@ -271,18 +271,95 @@ fn stop_baseline_write_create_is_new_but_missing_update_preimage_is_unknown() {
 
 #[test]
 fn stop_baseline_unknown_notice_respects_small_output_budget() {
+    for (budget, stale) in [(500, false), (500, true), (8000, true)] {
+        let t = Tmp::new();
+        let cwd = t.path();
+        t.write("package.json", "{}");
+        t.write(".impeccable/config.json", &json!({"hook":{"limits":{"maxChars":budget}}}).to_string());
+        let file = t.write("card.css", SIDE_TAB_CSS);
+        let r = rt(&cwd);
+        hook::run_hook(&r, &edit_event(&cwd, &file, "s1"));
+        if stale {
+            // Make the notice eligible only at Stop; no sleeps or clock races.
+            t.write("DESIGN.md", "---\nname: Test\n---\n");
+            let sidecar = t.write(".impeccable/design.json", "{}");
+            std::fs::File::options().write(true).open(sidecar).unwrap()
+                .set_modified(std::time::UNIX_EPOCH + std::time::Duration::from_secs(1_600_000_000)).unwrap();
+            assert!(design_system_options(&read_config(&cwd), &cwd).md_newer_than_json());
+        }
+        let stop = hook::run_stop_hook(&r, &stop_event(&cwd, "s1"));
+        let output: Value = serde_json::from_str(&stop.stdout).unwrap();
+        let text = output["hookSpecificOutput"]["additionalContext"].as_str().unwrap();
+        assert!(text.encode_utf16().count() <= budget, "{text}");
+        assert!(text.contains("may predate this session"));
+        assert!(text.contains("[side-tab]"), "{text}");
+        assert!(text.contains("[attribution unknown]"), "{text}");
+        assert!(text.contains("card.css"), "{text}");
+        if stale {
+            assert_eq!(text.contains("DESIGN.md is newer"), budget > 500, "{text}");
+            let cache: Value = serde_json::from_str(&t.read(".impeccable/hook.cache.json")).unwrap();
+            assert_eq!(cache["sessions"]["s1"]["designNoteShown"] == json!(true), budget > 500);
+        }
+    }
+}
+
+#[test]
+fn stop_baseline_deduplicated_unknown_does_not_add_notice_to_new_finding() {
+    let t = Tmp::new();
+    let cwd = t.path();
+    t.write("package.json", "{}");
+    let r = rt(&cwd);
+    let old = t.write("old/card.css", SIDE_TAB_CSS);
+    hook::run_hook(&r, &edit_event(&cwd, &old, "s1"));
+    assert!(hook::run_stop_hook(&r, &stop_event(&cwd, "s1")).stdout.contains("[attribution unknown]"));
+    let new = t.write("new/card.css", SIDE_TAB_CSS);
+    // Use a verified create event (an empty Edit preimage is not trusted).
+    let create = json!({"cwd": cwd, "session_id": "s1", "tool_name": "Write",
+        "tool_input": {"file_path": new, "content": SIDE_TAB_CSS},
+        "tool_response": {"type": "create", "filePath": new, "content": SIDE_TAB_CSS, "originalFile": null}}).to_string();
+    hook::run_hook(&r, &create);
+    let stop = hook::run_stop_hook(&r, &stop_event(&cwd, "s1"));
+    assert_eq!(stop.audit["unknownFindings"], json!(1), "audit retains the full scan");
+    assert!(stop.stdout.contains("[new]"), "{}", stop.stdout);
+    assert!(!stop.stdout.contains("may predate this session"), "{}", stop.stdout);
+}
+
+#[test]
+fn stop_baseline_capped_unknown_does_not_add_notice_to_new_finding() {
+    let t = Tmp::new();
+    let cwd = t.path();
+    t.write("package.json", "{}");
+    t.write(".impeccable/config.json", r#"{"hook":{"limits":{"maxFindings":1}}}"#);
+    let r = rt(&cwd);
+    let new = t.write("new/card.css", SIDE_TAB_CSS);
+    hook::run_hook(&r, &edit_with_original(&cwd, &new, "s1", ".card {}", ".card {}", SIDE_TAB_CSS));
+    let old = t.write("old/card.css", SIDE_TAB_CSS);
+    hook::run_hook(&r, &edit_event(&cwd, &old, "s1"));
+    let stop = hook::run_stop_hook(&r, &stop_event(&cwd, "s1"));
+    assert_eq!(stop.audit["unknownFindings"], json!(1));
+    assert!(stop.stdout.contains("[new]"), "{}", stop.stdout);
+    assert!(!stop.stdout.contains("[attribution unknown]"), "{}", stop.stdout);
+    assert!(!stop.stdout.contains("may predate this session"), "{}", stop.stdout);
+}
+
+#[test]
+fn stop_baseline_small_grouped_output_keeps_finding_and_attribution() {
     let t = Tmp::new();
     let cwd = t.path();
     t.write("package.json", "{}");
     t.write(".impeccable/config.json", r#"{"hook":{"limits":{"maxChars":500}}}"#);
-    let file = t.write("card.css", SIDE_TAB_CSS);
     let r = rt(&cwd);
-    hook::run_hook(&r, &edit_event(&cwd, &file, "s1"));
+    for path in ["one/card.css", "two/card.css"] {
+        let file = t.write(path, SIDE_TAB_CSS);
+        hook::run_hook(&r, &edit_event(&cwd, &file, "s1"));
+    }
     let stop = hook::run_stop_hook(&r, &stop_event(&cwd, "s1"));
     let output: Value = serde_json::from_str(&stop.stdout).unwrap();
     let text = output["hookSpecificOutput"]["additionalContext"].as_str().unwrap();
     assert!(text.encode_utf16().count() <= 500, "{text}");
-    assert!(text.contains("may predate this session"));
+    assert!(text.contains("[side-tab]"), "{text}");
+    assert!(text.contains("[attribution unknown]"), "{text}");
+    assert!(text.contains("may predate this session"), "{text}");
 }
 
 #[test]