diff --git a/ue_mcp_server.py b/ue_mcp_server.py
index 881ac45..92c334e 100644
--- a/ue_mcp_server.py
+++ b/ue_mcp_server.py
@@ -28,15 +28,24 @@ def _engine_root() -> Path:
     return Path(p)
 
 
+_type_index_cache: dict[str, str] = {}
+_type_index_mtime: float = 0.0
+
+
 def _load_type_index() -> dict[str, str]:
-    """Returns {TypeName: relative_md_path}."""
-    idx = (_docs_root() / "type-index.txt").read_text()
-    result = {}
-    for line in idx.splitlines():
-        if ": " in line:
-            name, path = line.split(": ", 1)
-            result[name.strip()] = path.strip()
-    return result
+    """Returns {TypeName: relative_md_path}, reloading only if the file has changed."""
+    global _type_index_cache, _type_index_mtime
+    idx_path = _docs_root() / "type-index.txt"
+    mtime = idx_path.stat().st_mtime
+    if mtime != _type_index_mtime:
+        result = {}
+        for line in idx_path.read_text().splitlines():
+            if ": " in line:
+                name, path = line.split(": ", 1)
+                result[name.strip()] = path.strip()
+        _type_index_cache = result
+        _type_index_mtime = mtime
+    return _type_index_cache
 
 
 # ---------------------------------------------------------------------------