diff --git a/src/main/ai/prompt.ts b/src/main/ai/prompt.ts
index 147fc8f..a649ec2 100644
--- a/src/main/ai/prompt.ts
+++ b/src/main/ai/prompt.ts
@@ -17,6 +17,7 @@ ${candidates.map((c, i) => `  ${i + 1}. ${c.iso ?? '(ambiguous)'} — matched to
     ? `\nExisting vocabulary tags (most-used first): ${vocab.join(', ')}\nPrefer reusing a vocabulary tag when the meaning matches; create new tags only when the meaning is genuinely new.\n`
     : '';
 
+  // candidateBlock & vocabBlock are self-delimited with leading/trailing \n
   return `You organize raw personal notes into structured metadata.
 
 Today's date in Korea Standard Time (KST): ${todayKst}
diff --git a/tests/unit/prompt.test.ts b/tests/unit/prompt.test.ts
index e19cee6..6d27932 100644
--- a/tests/unit/prompt.test.ts
+++ b/tests/unit/prompt.test.ts
@@ -19,13 +19,13 @@ describe('prompt', () => {
     expect(out).toContain('Prefer reusing');
   });
 
-  it('vocab block appears between candidate block and JSON rules', () => {
+  it('vocab block appears after header and before JSON rules', () => {
     const out = buildPrompt('hello', '2026-05-02', [], ['design']);
-    const candidateIdx = out.indexOf("Today's date");
+    const headerIdx = out.indexOf("Today's date");
     const vocabIdx = out.indexOf('Existing vocabulary');
     const jsonRulesIdx = out.indexOf('Return a JSON object');
-    expect(candidateIdx).toBeGreaterThan(-1);
-    expect(vocabIdx).toBeGreaterThan(candidateIdx);
+    expect(headerIdx).toBeGreaterThan(-1);
+    expect(vocabIdx).toBeGreaterThan(headerIdx);
     expect(jsonRulesIdx).toBeGreaterThan(vocabIdx);
   });
 });