diff --git a/src/mcp_synology_filestation/tools/filestation.py b/src/mcp_synology_filestation/tools/filestation.py
index af2dd8a..f6060cf 100644
--- a/src/mcp_synology_filestation/tools/filestation.py
+++ b/src/mcp_synology_filestation/tools/filestation.py
@@ -805,7 +805,7 @@ def register_filestation(
         if not taskid:
             return "Error: DSM did not return a task ID."
 
-        ok, result = await _poll_task("SYNO.FileStation.DirSize", 2, taskid)
+        ok, result = await _poll_task("SYNO.FileStation.DirSize", 1, taskid)
         if not ok:
             return result  # type: ignore[return-value]
 
diff --git a/test_dirsize_md5.py b/test_dirsize_md5.py
new file mode 100644
index 0000000..1db1166
--- /dev/null
+++ b/test_dirsize_md5.py
@@ -0,0 +1,133 @@
+"""Wegwerfskript: DirSize + MD5 direkt gegen die NAS testen.
+
+Ergebnisse der Versionsanalyse (vollständig):
+  DirSize: start v2, status v1
+  MD5:     start v2, status v1
+    - Wichtig: MD5-Status ist ONE-SHOT — nach dem ersten erfolgreichen
+      Abruf verfällt die Task-ID sofort (code 599 bei allen Folgeabfragen).
+    - Erster status-Aufruf muss direkt nach start kommen (delay~0).
+
+DirSize status-Response Felder:
+  finished: bool
+  num_dir:  int   (Anzahl Unterordner)
+  num_file: int   (Anzahl Dateien)
+  total_size: int (Gesamtgrösse in Bytes)
+
+MD5 status-Response Felder:
+  finished: bool
+  md5:      str   (Hex-String, 32 Zeichen)
+
+Ausführen: uv run python test_dirsize_md5.py
+"""
+
+import asyncio
+import json
+
+import httpx
+
+from mcp_synology_filestation.auth import AuthManager
+from mcp_synology_filestation.client import FileStationClient
+from mcp_synology_filestation.config import load_config
+
+DIRSIZE_PATH = "/test-mcp"
+MD5_PATH = "/test-mcp/test.zip"
+
+
+def pp(label: str, data: object) -> None:
+    print(f"\n{'='*60}")
+    print(f"  {label}")
+    print("=" * 60)
+    print(json.dumps(data, indent=2, ensure_ascii=False))
+
+
+async def raw(http: httpx.AsyncClient, base_url: str, sid: str, **params) -> dict:
+    r = await http.get(f"{base_url}/webapi/entry.cgi", params={"_sid": sid, **params})
+    r.raise_for_status()
+    try:
+        return r.json()
+    except Exception:
+        return {"_raw": r.text[:300], "_http_status": r.status_code}
+
+
+async def main() -> None:
+    config = load_config()
+    auth = AuthManager(config)
+
+    async with FileStationClient(config.base_url, config.connection.verify_ssl) as client:
+        client.set_auth_manager(auth)
+        await client._ensure_initialized()  # noqa: SLF001
+        sid = client.sid
+        base = config.base_url
+        print(f"[*] SID: {'OK' if sid else 'MISSING'}")
+
+        async with httpx.AsyncClient(verify=config.connection.verify_ssl, timeout=30.0) as http:
+
+            # ── DirSize: start v2, status v1 ─────────────────────────────
+            print(f"\n{'#'*60}")
+            print("  SYNO.FileStation.DirSize  (start v2, status v1)")
+            print(f"{'#'*60}")
+
+            start_body = await raw(
+                http, base, sid,
+                api="SYNO.FileStation.DirSize", version="2", method="start",
+                path=json.dumps([DIRSIZE_PATH]),
+            )
+            pp("DirSize::start", start_body)
+
+            taskid = (start_body.get("data") or {}).get("taskid")
+            if taskid:
+                for attempt in range(1, 11):
+                    await asyncio.sleep(0.2)
+                    status_body = await raw(
+                        http, base, sid,
+                        api="SYNO.FileStation.DirSize", version="1", method="status",
+                        taskid=taskid,
+                    )
+                    pp(f"DirSize::status (attempt {attempt})", status_body)
+                    data = (status_body.get("data") or {})
+                    if data.get("finished"):
+                        print("\n[*] FINISHED. Fields:")
+                        for k, v in data.items():
+                            print(f"    {k!r}: {type(v).__name__} = {v!r}")
+                        break
+
+            # ── MD5: start v2, status v1 (one-shot!) ─────────────────────
+            print(f"\n{'#'*60}")
+            print("  SYNO.FileStation.MD5  (start v2, status v1, ONE-SHOT)")
+            print(f"{'#'*60}")
+
+            start_body = await raw(
+                http, base, sid,
+                api="SYNO.FileStation.MD5", version="2", method="start",
+                file_path=json.dumps(MD5_PATH),
+            )
+            pp("MD5::start", start_body)
+
+            taskid = (start_body.get("data") or {}).get("taskid")
+            if taskid:
+                # Immediately poll status v1 — one-shot window, don't delay
+                for attempt in range(1, 6):
+                    if attempt > 1:
+                        await asyncio.sleep(0.05)
+                    status_body = await raw(
+                        http, base, sid,
+                        api="SYNO.FileStation.MD5", version="1", method="status",
+                        taskid=taskid,
+                    )
+                    pp(f"MD5::status (attempt {attempt})", status_body)
+                    data = (status_body.get("data") or {})
+                    if data.get("finished"):
+                        print("\n[*] FINISHED. Fields:")
+                        for k, v in data.items():
+                            print(f"    {k!r}: {type(v).__name__} = {v!r}")
+                        break
+                    if not status_body.get("success"):
+                        print("[!] 599 — task window closed, done probing.")
+                        break
+
+        await auth.logout(client)
+        print("\n[*] Logout OK.")
+
+
+if __name__ == "__main__":
+    asyncio.run(main())