diff --git a/python/packages/core/agent_framework/_harness/_memory.py b/python/packages/core/agent_framework/_harness/_memory.py
index c3f02f883b5..27c66e4d144 100644
--- a/python/packages/core/agent_framework/_harness/_memory.py
+++ b/python/packages/core/agent_framework/_harness/_memory.py
@@ -924,6 +924,8 @@ def search_transcripts(
         normalized_query = query.strip()
         if not normalized_query:
             raise ValueError("query must not be empty.")
+        if limit <= 0:
+            return []
         query_casefold = normalized_query.casefold()
         transcripts_directory = self.get_transcripts_directory(session, source_id=source_id)
         if not transcripts_directory.exists():
diff --git a/python/packages/core/tests/core/test_harness_memory.py b/python/packages/core/tests/core/test_harness_memory.py
index 464255d0b43..7d004e764f3 100644
--- a/python/packages/core/tests/core/test_harness_memory.py
+++ b/python/packages/core/tests/core/test_harness_memory.py
@@ -340,6 +340,21 @@ async def test_search_transcripts_returns_nothing_for_unknown_session(tmp_path)
     )
 
 
+async def test_search_transcripts_non_positive_limit_returns_nothing(tmp_path) -> None:
+    """A non-positive limit must return no results, not a single row."""
+    session = AgentSession(session_id="session-1")
+    session.state["owner_id"] = "user-1"
+    store = MemoryFileStore(tmp_path, owner_state_key="owner_id")
+    await _write_transcript(store, session, "session-1", "Matching transcript.")
+
+    assert store.search_transcripts(
+        session, source_id=DEFAULT_MEMORY_SOURCE_ID, query="transcript", limit=0
+    ) == []
+    assert store.search_transcripts(
+        session, source_id=DEFAULT_MEMORY_SOURCE_ID, query="transcript", limit=-1
+    ) == []
+
+
 def test_memory_file_store_rejects_owner_path_traversal(tmp_path) -> None:
     """Owner IDs with path traversal segments should not escape ``base_path``."""
     session = AgentSession(session_id="session-1")