diff --git a/tests/unit/service/test_customer_service_search_query.py b/tests/unit/service/test_customer_service_search_query.py
index aca9035..cf63daf 100644
--- a/tests/unit/service/test_customer_service_search_query.py
+++ b/tests/unit/service/test_customer_service_search_query.py
@@ -1,14 +1,22 @@
-"""客服检索问句构造的单元测试：什么时候该带上文，什么时候绝不能带。
+"""客服检索问句构造的单元测试：什么时候带上文、带什么、绝不带什么。
 
-背景是实测出来的：**无条件**拼接上文会让客户换话题时答非所问——同一会话先问
-「季季盈90天的起投金额是多少」，再问「基金赎回几天到账」，第二问的检索词变成两句话的
-混合，结果命中季季盈的产品块、答出产品介绍，而客户问的是赎回到账时间。
+背景全部来自实测，不是设想：
+
+1. **不能无条件带上文**。同一会话先问「季季盈90天的起投金额是多少」、再问
+   「基金赎回几天到账」，无条件拼接会让第二问命中季季盈的产品块、答出产品介绍。
+2. **带上文时不能带上一轮的原话**。把整句拼进来会让检索词语义变"宽"，反而只命中
+   粗粒度的整节块：实测「季季盈90天起投多少 那它风险高吗」拿到的是整个产品小节，
+   客户问的"风险"完全没被聚焦；换成「南方季季盈90天 那它风险高吗」才命中"风险等级"那一行。
+   上文的作用是**补主语**，不是**补内容**。
 """
 
 from app.core.contracts import AgentRequest, ConversationTurn
 from app.service.agent.implementations.customer_service import CustomerServiceAgent
 
 PREVIOUS = "季季盈90天的起投金额是多少"
+ANSWER = "南方季季盈90天：起投金额 1万元"
+TOPIC = "南方季季盈90天"
+FALLBACK = "抱歉，这个问题我暂时无法给出准确答复。建议您拨打客服热线 400-XXX-XXXX 转人工客服咨询。"
 
 
 def _request(message: str, *history: str) -> AgentRequest:
@@ -25,26 +33,59 @@ def _request(message: str, *history: str) -> AgentRequest:
     )
 
 
+def test_topic_extracted_from_row_block() -> None:
+    """行级块的回答：首个冒号前就是产品名。"""
+    assert CustomerServiceAgent._topic_of(ANSWER) == TOPIC
+
+
+def test_topic_extracted_from_section_block() -> None:
+    """整节块的回答：首个标题行去掉 # 号。"""
+    assert CustomerServiceAgent._topic_of(
+        "### 2.1 南方季季盈90天\n\n| 项目 | 详情 |\n|------|------|"
+    ) == "2.1 南方季季盈90天"
+
+
+def test_fallback_answer_yields_no_topic() -> None:
+    """兜底话术不是主题：拿它当检索主语只会把问题带偏，宁可退化。"""
+    assert CustomerServiceAgent._topic_of(FALLBACK) == ""
+    assert CustomerServiceAgent._topic_of("") == ""
+
+
 def test_topic_change_does_not_drag_previous_question_in() -> None:
-    """客户换话题时，检索词里不能出现上一轮的问题（实测的答非所问场景）。"""
-    query = CustomerServiceAgent._search_query(_request("基金赎回几天到账", PREVIOUS))
+    """客户换话题时，检索词里不能出现上一轮的痕迹（实测的答非所问场景）。"""
+    query = CustomerServiceAgent._search_query(_request("基金赎回几天到账", PREVIOUS, ANSWER))
 
     assert query == "基金赎回几天到账"
     assert "季季盈" not in query
 
 
-def test_referring_phrase_brings_context_in() -> None:
-    """带明确指代词的问句要靠上文补全主语。"""
-    query = CustomerServiceAgent._search_query(_request("这个产品的费率是多少", PREVIOUS))
+def test_referring_phrase_brings_topic_in() -> None:
+    """带明确指代词的问句要靠上文补主语。"""
+    query = CustomerServiceAgent._search_query(_request("这个产品的费率是多少", PREVIOUS, ANSWER))
 
-    assert PREVIOUS in query
+    assert query == f"{TOPIC} 这个产品的费率是多少"
 
 
-def test_very_short_question_brings_context_in() -> None:
-    """短到不构成完整意图的问句同样需要上文（"那它风险高吗"只有 6 个字）。"""
-    query = CustomerServiceAgent._search_query(_request("那它风险高吗", PREVIOUS))
+def test_very_short_question_brings_topic_in() -> None:
+    """短到不构成完整意图的问句同样需要主语（"那它风险高吗"只有 6 个字）。"""
+    query = CustomerServiceAgent._search_query(_request("那它风险高吗", PREVIOUS, ANSWER))
 
-    assert PREVIOUS in query
+    assert query == f"{TOPIC} 那它风险高吗"
+
+
+def test_previous_question_text_is_not_carried_in() -> None:
+    """只补主语、不补内容：上一轮的问句原话一个字都不能进检索词。"""
+    query = CustomerServiceAgent._search_query(_request("那它风险高吗", PREVIOUS, ANSWER))
+
+    assert PREVIOUS not in query
+    assert "起投金额" not in query
+
+
+def test_fallback_history_degrades_to_current_message_only() -> None:
+    """上一轮是兜底话术时取不出主语，退化为只查当前这一句，而不是瞎猜。"""
+    query = CustomerServiceAgent._search_query(_request("那它风险高吗", PREVIOUS, FALLBACK))
+
+    assert query == "那它风险高吗"
 
 
 def test_first_turn_has_no_history_to_add() -> None: