diff --git a/mempalace/cli.py b/mempalace/cli.py
index 3244c8b..6acfcb4 100644
--- a/mempalace/cli.py
+++ b/mempalace/cli.py
@@ -170,7 +170,7 @@ def cmd_repair(args):
     """Rebuild palace vector index from SQLite metadata."""
     import chromadb
     import shutil
-    from .migrate import confirm_destructive_action, has_palace_database
+    from .migrate import confirm_destructive_action, contains_palace_database
 
     palace_path = os.path.abspath(
         os.path.expanduser(args.palace) if args.palace else MempalaceConfig().palace_path
@@ -180,7 +180,7 @@ def cmd_repair(args):
     if not os.path.isdir(palace_path):
         print(f"\n  No palace found at {palace_path}")
         return
-    if not has_palace_database(palace_path):
+    if not contains_palace_database(palace_path):
         print(f"\n  No palace database found at {db_path}")
         return
 
@@ -226,8 +226,11 @@ def cmd_repair(args):
     palace_path = palace_path.rstrip(os.sep)
     backup_path = palace_path + ".backup"
     if os.path.exists(backup_path):
-        if not has_palace_database(backup_path):
-            print(f"  Refusing to delete non-palace backup path: {backup_path}")
+        if not contains_palace_database(backup_path):
+            print(
+                "  Cannot proceed: backup path exists but is not a valid palace database. "
+                f"Please remove or rename: {backup_path}"
+            )
             return
         shutil.rmtree(backup_path)
     print(f"  Backing up to {backup_path}...")
diff --git a/mempalace/migrate.py b/mempalace/migrate.py
index 715511d..6410801 100644
--- a/mempalace/migrate.py
+++ b/mempalace/migrate.py
@@ -104,7 +104,7 @@ def detect_chromadb_version(db_path: str) -> str:
         conn.close()
 
 
-def has_palace_database(path: str) -> bool:
+def contains_palace_database(path: str) -> bool:
     """Return True when path looks like a MemPalace ChromaDB directory."""
     return os.path.isfile(os.path.join(path, "chroma.sqlite3"))
 
@@ -135,7 +135,7 @@ def migrate(palace_path: str, dry_run: bool = False, confirm: bool = False):
     palace_path = os.path.abspath(os.path.expanduser(palace_path))
     db_path = os.path.join(palace_path, "chroma.sqlite3")
 
-    if not os.path.isdir(palace_path) or not has_palace_database(palace_path):
+    if not os.path.isdir(palace_path) or not contains_palace_database(palace_path):
         print(f"\n  No palace database found at {db_path}")
         return False
 
diff --git a/tests/test_query_sanitizer.py b/tests/test_query_sanitizer.py
index 2a5c94b..015a8a1 100644
--- a/tests/test_query_sanitizer.py
+++ b/tests/test_query_sanitizer.py
@@ -102,6 +102,20 @@ class TestTailSentence:
         assert result["was_sanitized"] is True
         assert "MemPalace" in result["clean_query"] or "ChromaDB" in result["clean_query"]
 
+    def test_long_candidate_uses_last_sentence_fragment(self):
+        query = ("Prompt sentence. " * 30) + "Final search intent for architecture migration"
+        result = sanitize_query(query)
+        assert result["method"] == "tail_sentence"
+        assert result["clean_query"] == "Final search intent for architecture migration"
+
+    def test_long_candidate_strips_wrapping_quotes(self):
+        query = ("Prefix text " * 30) + '\n"' + ("x" * 260) + '"'
+        result = sanitize_query(query)
+        assert result["method"] == "tail_sentence"
+        assert not result["clean_query"].startswith('"')
+        assert not result["clean_query"].endswith('"')
+        assert len(result["clean_query"]) <= MAX_QUERY_LENGTH
+
 
 class TestTailTruncation:
     """Step 4: Fallback — take the last MAX_QUERY_LENGTH characters."""
@@ -119,6 +133,12 @@ class TestTailTruncation:
         result = sanitize_query(filler)
         assert "IMPORTANT_QUERY_CONTENT" in result["clean_query"]
 
+    def test_tail_sentence_fallback_preserves_tail_without_delimiters(self):
+        filler = ("x" * 260) + "IMPORTANT_QUERY_CONTENT"
+        result = sanitize_query(filler)
+        assert result["method"] == "tail_sentence"
+        assert "IMPORTANT_QUERY_CONTENT" in result["clean_query"]
+
 
 class TestLengthGuards:
     """Verify output length constraints."""