diff --git a/paperforge/commands/sync.py b/paperforge/commands/sync.py
index de4f31b7..5c2a8099 100644
--- a/paperforge/commands/sync.py
+++ b/paperforge/commands/sync.py
@@ -83,7 +83,8 @@ def run(args: argparse.Namespace) -> int:
     try:
         from paperforge.memory.builder import build_from_index
         counts = build_from_index(vault)
-        print(f"memory: {counts.get('papers_indexed', 0)} papers indexed")
+        tag = " (fast)" if counts.get("hash_match") else ""
+        print(f"memory: {counts.get('papers_indexed', 0)} papers{tag}")
     except Exception as e:
         print(f"memory: deferred ({e})")
 
diff --git a/paperforge/memory/builder.py b/paperforge/memory/builder.py
index 3367964e..51bbd5c7 100644
--- a/paperforge/memory/builder.py
+++ b/paperforge/memory/builder.py
@@ -155,6 +155,7 @@ def build_from_index(vault: Path) -> dict:
             if cached and cached[0] == canonical_hash and stored_version == CURRENT_SCHEMA_VERSION:
                 papers_count = conn.execute("SELECT COUNT(*) FROM papers").fetchone()[0]
                 conn.close()
+                logger.info("Index unchanged, skipping memory rebuild (%s papers)", papers_count)
                 return {
                     "papers_indexed": papers_count,
                     "db_path": str(db_path),