diff --git a/surfsense_backend/tests/unit/agents/multi_agent_chat/tools/test_search_knowledge_base.py b/surfsense_backend/tests/unit/agents/multi_agent_chat/tools/test_search_knowledge_base.py
new file mode 100644
index 000000000..eadfcd30d
--- /dev/null
+++ b/surfsense_backend/tests/unit/agents/multi_agent_chat/tools/test_search_knowledge_base.py
@@ -0,0 +1,79 @@
+"""Unit tests for search_knowledge_base hit rendering.
+
+The tool must surface the passage that actually matched (the RRF-ranked
+chunk), not the top of the document, and annotate it with its line range
+when the chunk carries a char span.
+"""
+
+from __future__ import annotations
+
+import pytest
+
+from app.agents.chat.multi_agent_chat.main_agent.tools.search_knowledge_base import (
+    _format_hits,
+)
+
+pytestmark = pytest.mark.unit
+
+_BODY = "Intro paragraph.\n\nMatched passage here.\n\nClosing paragraph."
+
+
+def _hit() -> dict:
+    intro = "Intro paragraph."
+    matched = "Matched passage here."
+    matched_start = _BODY.index(matched)
+    return {
+        "document": {"id": 7, "title": "note.md", "document_type": "NOTE"},
+        "score": 0.42,
+        "content": _BODY.replace("\n\n", "\n\n"),
+        "matched_chunk_ids": [102],
+        "chunks": [
+            {
+                "chunk_id": 101,
+                "content": intro,
+                "start_char": 0,
+                "end_char": len(intro),
+            },
+            {
+                "chunk_id": 102,
+                "content": matched,
+                "start_char": matched_start,
+                "end_char": matched_start + len(matched),
+            },
+        ],
+    }
+
+
+def test_renders_matched_passage_not_top_of_doc() -> None:
+    out = _format_hits([_hit()], paths={7: "/documents/note.md"}, bodies={7: _BODY}, query="q")
+    assert "Matched passage here." in out
+    # The intro chunk was not matched, so it must not be shown as the snippet.
+    assert "Intro paragraph." not in out
+
+
+def test_includes_line_range_when_spans_present() -> None:
+    out = _format_hits([_hit()], paths={7: "/documents/note.md"}, bodies={7: _BODY}, query="q")
+    # "Matched passage here." sits on line 3 of the body.
+    assert "line 3" in out
+
+
+def test_omits_line_range_when_spans_absent() -> None:
+    hit = _hit()
+    for chunk in hit["chunks"]:
+        chunk["start_char"] = None
+        chunk["end_char"] = None
+    out = _format_hits([hit], paths={7: "/documents/note.md"}, bodies={7: _BODY}, query="q")
+    assert "Matched passage here." in out
+    assert "[line" not in out
+
+
+def test_falls_back_to_content_when_no_matched_ids() -> None:
+    hit = _hit()
+    hit["matched_chunk_ids"] = []
+    out = _format_hits([hit], paths={7: "/documents/note.md"}, bodies={7: _BODY}, query="q")
+    assert "Intro paragraph." in out
+
+
+def test_no_results_message() -> None:
+    out = _format_hits([], paths={}, bodies={}, query="missing")
+    assert "No knowledge-base matches" in out