diff --git a/scripts/atocore_mcp.py b/scripts/atocore_mcp.py
index 9474e13..13f382d 100644
--- a/scripts/atocore_mcp.py
+++ b/scripts/atocore_mcp.py
@@ -37,6 +37,17 @@ import urllib.error
 import urllib.parse
 import urllib.request
 
+# Force UTF-8 on stdio — MCP protocol expects UTF-8 but Windows Python
+# defaults stdout to cp1252, which crashes on any non-ASCII char (emojis,
+# ≥, →, etc.) in tool responses. This call is a no-op on Linux/macOS
+# where UTF-8 is already the default.
+try:
+    sys.stdin.reconfigure(encoding="utf-8")
+    sys.stdout.reconfigure(encoding="utf-8")
+    sys.stderr.reconfigure(encoding="utf-8")
+except Exception:
+    pass
+
 # --- Configuration ---
 
 ATOCORE_URL = os.environ.get("ATOCORE_URL", "http://dalidou:8100").rstrip("/")