diff --git a/contracts/ad-slot.schema.json b/contracts/ad-slot.schema.json
index af63149e..a872d6fa 100644
--- a/contracts/ad-slot.schema.json
+++ b/contracts/ad-slot.schema.json
@@ -18,7 +18,7 @@
       "enum": ["rewarded", "interstitial", "banner"]
     },
     "provider": {
-      "description": "广告联盟：csj=穿山甲 / gdt=优量汇 / mock=桩（MVP 默认）/ callback=sandbox 自回调桩（M4 服务端回调验签演进，签名校验走桩直通；见 api-schemas/ad.yaml /app-api/ad/reward/callback 与 ad 模块 CallbackAdProvider）",
+      "description": "广告联盟：csj=穿山甲 / gdt=优量汇 / mock=桩（MVP 默认）/ callback=sandbox 自回调桩（M4 服务端回调验签演进，真验签走 MD5 桩算法、空密钥拒绝，非直通放行；见 api-schemas/ad.yaml /app-api/ad/reward/callback 与 ad 模块 CallbackAdProvider）",
       "type": "string",
       "enum": ["csj", "gdt", "mock", "callback"]
     },