diff --git a/connect-vpn/action.yml b/connect-vpn/action.yml
index f544a5b..46fb8fe 100644
--- a/connect-vpn/action.yml
+++ b/connect-vpn/action.yml
@@ -181,6 +181,25 @@ runs:
           curl -k -sS --http1.1 -A "$UA" "$@"
         }
 
+        summarize_html() {
+          page="$1"
+          if [ ! -f "$page" ]; then
+            return
+          fi
+          title="$(sed -n 's/.*<title>\(.*\)<\/title>.*/\1/ip' "$page" | head -1 | tr -d '\r' || true)"
+          if [ -n "$title" ]; then
+            echo "응답 title: $title"
+          fi
+          if grep -q "ga_code_attempt" "$page"; then
+            echo "응답 상태: OTP 입력 폼이 다시 표시됨"
+          fi
+          sed 's/<[^>]*>/\n/g' "$page" |
+            sed 's/&nbsp;/ /g; s/&amp;/\&/g; s/^[[:space:]]*//; s/[[:space:]]*$//' |
+            grep -Eai 'incorrect|invalid|denied|failed|failure|error|otp|password|인증|실패|오류|잘못|거부' |
+            grep -Ev '^$' |
+            head -10 || true
+        }
+
         echo "F5 웹 로그인 시작: ${VPN_HOST} (user=${VPN_USER})"
         curl_common -L -c "$COOKIE_JAR" "$VPN_HOST/" -o "$WORKDIR/01-login.html"
 
@@ -206,11 +225,6 @@ runs:
           --data-urlencode "vhost=standard" \
           -o "$WORKDIR/03-webtop.html"
 
-        if ! grep -q "F5 Dynamic Webtop\|Network Access" "$WORKDIR/03-webtop.html"; then
-          echo "OTP 인증 후 Webtop에 도달하지 못했습니다."
-          exit 1
-        fi
-
         host_no_scheme="${VPN_HOST#https://}"
         host_no_scheme="${host_no_scheme#http://}"
         host_no_scheme="${host_no_scheme%%/*}"
@@ -231,6 +245,8 @@ runs:
         )"
         if [ -z "$otc" ]; then
           echo "F5 session token 획득 실패"
+          summarize_html "$WORKDIR/03-webtop.html"
+          summarize_html "$WORKDIR/04-token.body"
           exit 1
         fi