diff --git a/.changeset/silly-jaguars-caper.md b/.changeset/silly-jaguars-caper.md
new file mode 100644
index 000000000..41e0bde92
--- /dev/null
+++ b/.changeset/silly-jaguars-caper.md
@@ -0,0 +1,5 @@
+---
+type: Fixed
+pr: 3401
+---
+**`milestone.complete` no longer records the wrong line as a release's accomplishment** — the one-liner was extracted from the first bold text under the SUMMARY's first heading, so an incidental first heading (a rule list, deviation notes) could contribute `Rule 1 - Bug` or `NeutralPath` as the milestone's permanent accomplishment in MILESTONES.md. Extraction now anchors to a Summary/Overview/Accomplishments heading and falls back to empty when none is present. (#3170)
diff --git a/src/core-utils.cts b/src/core-utils.cts
index 5f142ffc4..105cf9ea6 100644
--- a/src/core-utils.cts
+++ b/src/core-utils.cts
@@ -70,15 +70,26 @@ function extractOneLinerFromBody(content: string | null | undefined): string | n
   if (!content) return null;
   const normalized = content.replace(/\r\n/g, '\n').replace(/\r/g, '\n');
   const body = normalized.replace(/^---\n[\s\S]*?\n---\n*/, '');
-  const match = body.match(/^#[^\n]*\n+\*\*([^*\n]+)\*\*([^\n]*)/m);
-  if (!match) return null;
-  const boldInner = match[1].trim();
-  const afterBold = match[2];
-  if (/:\s*$/.test(boldInner)) {
-    const prose = afterBold.trim();
-    return prose.length > 0 ? prose : null;
+  // #3170: anchor to a summary-shaped heading (Summary / Overview /
+  // Accomplishments) so an incidental first heading (a rule list, task
+  // breakdown, deviation note) does not contribute its first bold run as the
+  // deliverable one-liner. Iterate headings in document order and extract from
+  // the first summary-shaped one that has a bold run; fall back to null (not the
+  // wrong text) when no such heading exists.
+  const headingRe = /^#+\s*([^\n]*)\n+\*\*([^*\n]+)\*\*([^\n]*)/gm;
+  let match: RegExpExecArray | null;
+  while ((match = headingRe.exec(body)) !== null) {
+    if (!/summary|overview|accomplish/i.test(match[1])) continue;
+    const boldInner = match[2].trim();
+    const afterBold = match[3];
+    if (/:\s*$/.test(boldInner)) {
+      const prose = afterBold.trim();
+      if (prose.length > 0) return prose;
+    } else if (boldInner.length > 0) {
+      return boldInner;
+    }
   }
-  return boldInner.length > 0 ? boldInner : null;
+  return null;
 }
 
 // ─── Misc utilities ───────────────────────────────────────────────────────────
diff --git a/tests/core-utils.test.cjs b/tests/core-utils.test.cjs
index 67075d410..499f742a6 100644
--- a/tests/core-utils.test.cjs
+++ b/tests/core-utils.test.cjs
@@ -502,33 +502,38 @@ describe('extractOneLinerFromBody', () => {
     assert.strictEqual(coreUtils.extractOneLinerFromBody(''), null);
   });
 
+  // #3170: extractOneLinerFromBody anchors to a Summary/Overview/Accomplishments
+  // heading (the function is summary-specific — both callers extract a SUMMARY
+  // deliverable one-liner). These fixtures use Summary-shaped headings; the
+  // extraction mechanism under test (heading + bold → bold, frontmatter strip,
+  // colon-label → prose, CRLF, unicode) is unchanged.
   test('extracts bold text after a heading as one-liner', () => {
-    const content = '# Phase Title\n\n**Implement the feature**\n\nMore details here.\n';
+    const content = '# Phase Summary\n\n**Implement the feature**\n\nMore details here.\n';
     assert.strictEqual(coreUtils.extractOneLinerFromBody(content), 'Implement the feature');
   });
 
   test('returns null when no bold text after heading', () => {
-    const content = '# Phase Title\n\nSome prose without bold.\n';
+    const content = '# Phase Summary\n\nSome prose without bold.\n';
     assert.strictEqual(coreUtils.extractOneLinerFromBody(content), null);
   });
 
   test('strips frontmatter before searching', () => {
-    const content = '---\nstatus: done\n---\n# Title\n\n**One liner here**\n';
+    const content = '---\nstatus: done\n---\n# Summary\n\n**One liner here**\n';
     assert.strictEqual(coreUtils.extractOneLinerFromBody(content), 'One liner here');
   });
 
   test('when bold ends with colon, returns text after the bold', () => {
-    const content = '# Title\n\n**Objective:** Complete the work\n';
+    const content = '# Summary\n\n**Objective:** Complete the work\n';
     assert.strictEqual(coreUtils.extractOneLinerFromBody(content), 'Complete the work');
   });
 
   test('CRLF line endings are normalized', () => {
-    const content = '# Title\r\n\r\n**Bold line**\r\nmore\r\n';
+    const content = '# Summary\r\n\r\n**Bold line**\r\nmore\r\n';
     assert.strictEqual(coreUtils.extractOneLinerFromBody(content), 'Bold line');
   });
 
   test('adversarial: unicode in bold text', () => {
-    const content = '# Title\n\n**中文 one-liner**\n\nMore.\n';
+    const content = '# Summary\n\n**中文 one-liner**\n\nMore.\n';
     assert.strictEqual(coreUtils.extractOneLinerFromBody(content), '中文 one-liner');
   });
 });
diff --git a/tests/milestone.test.cjs b/tests/milestone.test.cjs
index bdefd314b..7ee976af3 100644
--- a/tests/milestone.test.cjs
+++ b/tests/milestone.test.cjs
@@ -2106,6 +2106,60 @@ describe('bug #2660: extractOneLinerFromBody', () => {
 }
 
 // ────────────────────────────────────────────────────────────────────────
+describe('#3170: extractOneLinerFromBody anchors to a summary-shaped heading', () => {
+  // Self-contained require (the #2660 block's require is fold-scoped).
+  const path = require('path');
+  const { extractOneLinerFromBody } = require(
+    path.join(__dirname, '..', 'gsd-core', 'bin', 'lib', 'core-utils.cjs')
+  );
+
+  test('row 1 — an incidental first heading does not contribute its bold run; the Summary heading does', () => {
+    const content = [
+      '# Rules',
+      '',
+      '**Rule 1 - Bug** Task 2 spawned a real agent CLI process on first attempt.',
+      '',
+      '## Summary',
+      '',
+      '**Shipped unattended dogfooding resume.** Real deliverable description.',
+      '',
+    ].join('\n');
+    assert.strictEqual(
+      extractOneLinerFromBody(content),
+      'Shipped unattended dogfooding resume.',
+      `must anchor to the Summary heading, not the incidental # Rules one`
+    );
+  });
+
+  test('row 2 — no summary-shaped heading at all returns null (not the wrong text)', () => {
+    const content = [
+      '# Deviation Notes',
+      '',
+      '**NeutralPath** is the production fix.',
+      '',
+      '## Follow-ups',
+      '',
+      '**The production fix is one expression.** Not a deliverable summary.',
+      '',
+    ].join('\n');
+    assert.strictEqual(
+      extractOneLinerFromBody(content),
+      null,
+      `no Summary/Overview/Accomplishments heading → null, not incidental bold text`
+    );
+  });
+
+  test('row 3 — an Overview heading is recognized', () => {
+    const content = '# Overview\n\n**Shipped the thing.** Details follow.\n';
+    assert.strictEqual(extractOneLinerFromBody(content), 'Shipped the thing.');
+  });
+
+  test('row 4 — #2660 form (heading contains "Summary") is unchanged', () => {
+    const content = '# Phase 1: Foundation Summary\n\n**One-liner:** Real prose here.\n';
+    assert.strictEqual(extractOneLinerFromBody(content), 'Real prose here.');
+  });
+});
+
 // Folded from tests/enh-72-business-context.test.cjs — consolidation epic #1969 (B8 #1977)
 // ────────────────────────────────────────────────────────────────────────
 {