diff --git a/scripts/sync_standards.sh b/scripts/sync_standards.sh
index d61aab3..9b3de77 100644
--- a/scripts/sync_standards.sh
+++ b/scripts/sync_standards.sh
@@ -165,17 +165,92 @@ EOF
 fi
 
 AGENTS_MD="$ROOT/AGENTS.md"
-if [ ! -f "$AGENTS_MD" ]; then
-  cat >"$AGENTS_MD" <<'EOF'
-# Agent Instructions
-
-请以 `.agents/` 下的规则为准：
-
-- 入口：`.agents/index.md`
-- 语言规则：`.agents/tsl/index.md`、`.agents/cpp/index.md`、`.agents/python/index.md`、`.agents/markdown/index.md`
-EOF
-  echo "Created AGENTS.md"
+AGENTS_BLOCK_START="<!-- playbook:agents:start -->"
+AGENTS_BLOCK_END="<!-- playbook:agents:end -->"
+AGENTS_BLOCK_TMP="$(mktemp 2>/dev/null || echo "$ROOT/.agents_block.$timestamp")"
+agents_langs=""
+if [ -d "$AGENTS_ROOT" ]; then
+  for dir in "$AGENTS_ROOT"/*; do
+    [ -d "$dir" ] || continue
+    name="$(basename "$dir")"
+    case "$name" in
+      ""|.*|*.bak.*) continue ;;
+    esac
+    if [ -f "$dir/index.md" ]; then
+      agents_langs="${agents_langs:+$agents_langs }$name"
+    fi
+  done
 fi
+if [ -z "$agents_langs" ]; then
+  agents_langs="$AGENTS_NS"
+fi
+
+langs_line=""
+for name in $agents_langs; do
+  entry="`.agents/$name/index.md`"
+  if [ -z "$langs_line" ]; then
+    langs_line="$entry"
+  else
+    langs_line="$langs_line、$entry"
+  fi
+done
+
+{
+  printf "%s\n" "$AGENTS_BLOCK_START"
+  printf "%s\n\n" "请以 `.agents/` 下的规则为准："
+  printf "%s\n" "- 入口：`.agents/index.md`"
+  if [ -n "$langs_line" ]; then
+    printf "%s\n" "- 语言规则：$langs_line"
+  else
+    printf "%s\n" "- 语言规则："
+  fi
+  printf "%s\n" "$AGENTS_BLOCK_END"
+} >"$AGENTS_BLOCK_TMP"
+
+if [ ! -f "$AGENTS_MD" ]; then
+  {
+    printf "%s\n\n" "# Agent Instructions"
+    cat "$AGENTS_BLOCK_TMP"
+  } >"$AGENTS_MD"
+  echo "Created AGENTS.md"
+else
+  if grep -Fq "$AGENTS_BLOCK_START" "$AGENTS_MD"; then
+    tmp="$(mktemp 2>/dev/null || echo "$ROOT/.agents_md.$timestamp")"
+    awk -v start="$AGENTS_BLOCK_START" -v end="$AGENTS_BLOCK_END" -v block_file="$AGENTS_BLOCK_TMP" '
+      BEGIN {
+        while ((getline line < block_file) > 0) { block[++n] = line }
+        close(block_file)
+        inblock=0
+        replaced=0
+      }
+      {
+        if (!replaced && $0 == start) {
+          for (i=1; i<=n; i++) print block[i]
+          inblock=1
+          replaced=1
+          next
+        }
+        if (inblock) {
+          if ($0 == end) { inblock=0 }
+          next
+        }
+        print
+      }
+    ' "$AGENTS_MD" >"$tmp"
+    mv "$tmp" "$AGENTS_MD"
+    echo "Updated AGENTS.md (playbook block)."
+  else
+    if grep -Fq ".agents/index.md" "$AGENTS_MD"; then
+      echo "Skip: AGENTS.md already references .agents/index.md"
+    else
+      printf "\n" >>"$AGENTS_MD"
+      cat "$AGENTS_BLOCK_TMP" >>"$AGENTS_MD"
+      printf "\n" >>"$AGENTS_MD"
+      echo "Appended playbook block to AGENTS.md"
+    fi
+  fi
+fi
+rm -f "$AGENTS_BLOCK_TMP"
 
 echo "Synced agents ruleset to $AGENTS_DST."