diff --git a/plugin/index.ts b/plugin/index.ts
index 2c2f727..a1d5bc8 100644
--- a/plugin/index.ts
+++ b/plugin/index.ts
@@ -8,6 +8,7 @@ type DiscordControlAction = "channel-private-create" | "channel-private-update"
 type DecisionRecord = {
   decision: Decision;
   createdAt: number;
+  needsRestore?: boolean;
 };
 
 type PolicyState = {
@@ -168,7 +169,7 @@ function shouldDebugLog(cfg: DebugConfig, channelId?: string): boolean {
   if (!cfg.enableDebugLogs) return false;
   const allow = Array.isArray(cfg.debugLogChannelIds) ? cfg.debugLogChannelIds : [];
   if (allow.length === 0) return true;
-  if (!channelId) return false;
+  if (!channelId) return true; // 允许打印，方便排查 channelId 为空的场景
   return allow.includes(channelId);
 }
 
@@ -363,8 +364,18 @@ export default {
       ensurePolicyStateLoaded(api, live);
 
       const prompt = ((event as Record<string, unknown>).prompt as string) || "";
+      
+      if (live.enableDebugLogs) {
+        api.logger.info(
+          `whispergate: DEBUG_BEFORE_MODEL_RESOLVE ctx=${JSON.stringify({ sessionKey: ctx.sessionKey, messageProvider: ctx.messageProvider, agentId: ctx.agentId })} ` +
+            `promptPreview=${prompt.slice(0, 300)}`,
+        );
+      }
+
       const derived = deriveDecisionInputFromPrompt(prompt, ctx.messageProvider);
-      if (live.discordOnly !== false && derived.channel !== "discord") return;
+      // Only proceed if: discord channel AND prompt contains untrusted metadata
+      const hasConvMarker = prompt.includes("Conversation info (untrusted metadata):");
+      if (live.discordOnly !== false && (!hasConvMarker || derived.channel !== "discord")) return;
 
       let rec = sessionDecision.get(key);
       if (!rec || Date.now() - rec.createdAt > DECISION_TTL_MS) {
@@ -392,7 +403,36 @@ export default {
         }
       }
 
-      if (!rec.decision.shouldUseNoReply) return;
+      if (!rec.decision.shouldUseNoReply) {
+        // 如果之前有 no-reply 执行过，现在不需要了，清除 override 恢复原模型
+        if (rec.needsRestore) {
+          sessionDecision.delete(key);
+          return {
+            providerOverride: undefined,
+            modelOverride: undefined,
+          };
+        }
+        return;
+      }
+
+      // 标记这次执行了 no-reply，下次需要恢复模型
+      rec.needsRestore = true;
+      sessionDecision.set(key, rec);
+
+      // 无论是否有缓存，只要 debug flag 开启就打印决策详情
+      if (live.enableDebugLogs) {
+        const prompt = ((event as Record<string, unknown>).prompt as string) || "";
+        const hasConvMarker = prompt.includes("Conversation info (untrusted metadata):");
+        api.logger.info(
+          `whispergate: DEBUG_NO_REPLY_TRIGGER session=${key} ` +
+            `channel=${derived.channel} channelId=${derived.channelId ?? ""} senderId=${derived.senderId ?? ""} ` +
+            `convSenderId=${String((derived.conv as Record<string, unknown>).sender_id ?? "")} ` +
+            `convSender=${String((derived.conv as Record<string, unknown>).sender ?? "")} ` +
+            `decision=${rec.decision.reason} ` +
+            `shouldNoReply=${rec.decision.shouldUseNoReply} shouldInject=${rec.decision.shouldInjectEndMarkerPrompt} ` +
+            `hasConvMarker=${hasConvMarker} promptLen=${prompt.length}`,
+        );
+      }
 
       api.logger.info(
         `whispergate: override model for session=${key}, provider=${live.noReplyProvider}, model=${live.noReplyModel}, reason=${rec.decision.reason}`,