diff --git a/src/commands.ts b/src/commands.ts
index 627f79f..b4e3884 100644
--- a/src/commands.ts
+++ b/src/commands.ts
@@ -43,9 +43,9 @@ export async function handleCommand(
 
       return `📊 <b>현재 컨텍스트</b>
 
-분석된 메시지: ${ctx.previousSummary?.message_count || 0}개
+분석된 메시지: ${ctx.previousSummary?.message_count ?? 0}개
 버퍼 메시지: ${ctx.recentMessages.length}개
-프로필 버전: ${ctx.previousSummary?.generation || 0}
+프로필 버전: ${ctx.previousSummary?.generation ?? 0}
 총 메시지: ${ctx.totalMessages}개
 
 💡 ${remaining > 0 ? `${remaining}개 메시지 후 프로필 업데이트` : '업데이트 대기 중'}`;
@@ -78,12 +78,18 @@ ${summary.summary}
       return `📈 <b>대화 통계</b>
 
 총 메시지: ${ctx.totalMessages}개
-프로필 버전: ${ctx.previousSummary?.generation || 0}
-저장된 프로필: ${profileCount?.cnt || 0}개
+프로필 버전: ${ctx.previousSummary?.generation ?? 0}
+저장된 프로필: ${profileCount?.cnt ?? 0}개
 버퍼 대기: ${ctx.recentMessages.length}개`;
     }
 
     case '/debug': {
+      // Admin only - exposes internal debug info
+      const adminId = env.DEPOSIT_ADMIN_ID ? parseInt(env.DEPOSIT_ADMIN_ID, 10) : null;
+      if (!adminId || userId !== adminId) {
+        return '🔒 이 명령어는 관리자만 사용할 수 있습니다.';
+      }
+
       // 디버그용 명령어 (개발 시 유용)
       const ctx = await getConversationContext(env.DB, userId, chatId);
       const recentMsgs = ctx.recentMessages.slice(-5).map((m, i) =>
@@ -95,7 +101,7 @@ ${summary.summary}
 User ID: ${userId}
 Chat ID: ${chatId}
 Buffer Count: ${ctx.recentMessages.length}
-Summary Gen: ${ctx.previousSummary?.generation || 0}
+Summary Gen: ${ctx.previousSummary?.generation ?? 0}
 
 <b>최근 버퍼 (5개):</b>
 ${recentMsgs || '(비어있음)'}`;
diff --git a/src/deposit-agent.ts b/src/deposit-agent.ts
index 475b423..5058db2 100644
--- a/src/deposit-agent.ts
+++ b/src/deposit-agent.ts
@@ -20,6 +20,7 @@ const logger = createLogger('deposit-agent');
 
 const MIN_DEPOSIT_AMOUNT = 1000; // 1,000원
 const MAX_DEPOSIT_AMOUNT = 100_000_000; // 1억원
+const DEFAULT_HISTORY_LIMIT = 10;
 
 export interface DepositContext {
   userId: number;
@@ -197,8 +198,8 @@ export async function executeDepositFunction(
     }
 
     case 'get_transactions': {
-      // LIMIT 값 검증: 1-100 범위, 기본값 10
-      const limit = Math.min(Math.max(parseInt(String(funcArgs.limit)) || 10, 1), 100);
+      // LIMIT 값 검증: 1-100 범위
+      const limit = Math.min(Math.max(parseInt(String(funcArgs.limit)) || DEFAULT_HISTORY_LIMIT, 1), 100);
 
       const transactions = await db.prepare(
         `SELECT id, type, amount, status, depositor_name, description, created_at, confirmed_at
diff --git a/src/openai-service.ts b/src/openai-service.ts
index bc78266..cc9a5e8 100644
--- a/src/openai-service.ts
+++ b/src/openai-service.ts
@@ -413,7 +413,9 @@ export async function generateOpenAIResponse(
       const saveableInfo = extractSaveableInfo(userMessage);
       if (saveableInfo) {
         // 비동기로 저장, 응답 지연 없음
-        saveMemorySilently(db, telegramUserId, saveableInfo).catch(() => {});
+        saveMemorySilently(db, telegramUserId, saveableInfo).catch(err => {
+          logger.debug('Memory save failed (non-critical)', { error: (err as Error).message });
+        });
       }
 
       return finalResponse;
diff --git a/src/services/bank-sms-parser.ts b/src/services/bank-sms-parser.ts
index e91ad78..5cda688 100644
--- a/src/services/bank-sms-parser.ts
+++ b/src/services/bank-sms-parser.ts
@@ -4,6 +4,8 @@ import { createLogger } from '../utils/logger';
 
 const logger = createLogger('bank-sms-parser');
 
+const SMS_CONTENT_MAX_LENGTH = 500;
+
 /**
  * 은행 SMS 파싱 함수
  *
@@ -52,7 +54,7 @@ function preprocessText(content: string): string {
   // [Web발신] 또는 은행 키워드가 있는 부분만 추출
   const smsStartMatch = text.match(/ \[Web발신\]| \[하나은행\]| \[KB\]| \[신한\]| \[우리\]| \[농협\]/);
   if (smsStartMatch && smsStartMatch.index !== undefined) {
-    text = text.slice(smsStartMatch.index, smsStartMatch.index + 500);
+    text = text.slice(smsStartMatch.index, smsStartMatch.index + SMS_CONTENT_MAX_LENGTH);
   }
   return text;
 }
@@ -68,7 +70,7 @@ function parseWithRegex(text: string): BankNotification | null {
       depositorName: depositor.trim(),
       amount: parseInt(amountStr.replace(/,/g, '')),
       transactionTime: parseDateTime(date, time),
-      rawMessage: text.slice(0, 500),
+      rawMessage: text.slice(0, SMS_CONTENT_MAX_LENGTH),
     };
   }
 
@@ -83,7 +85,7 @@ function parseWithRegex(text: string): BankNotification | null {
       amount: parseInt(amountStr.replace(/,/g, '')),
       balanceAfter: balanceStr ? parseInt(balanceStr.replace(/,/g, '')) : undefined,
       transactionTime: parseDateTime(date, time),
-      rawMessage: text.slice(0, 500),
+      rawMessage: text.slice(0, SMS_CONTENT_MAX_LENGTH),
     };
   }
 
@@ -97,7 +99,7 @@ function parseWithRegex(text: string): BankNotification | null {
       depositorName: depositor,
       amount: parseInt(amountStr.replace(/,/g, '')),
       transactionTime: date ? parseDateTime(date, time) : undefined,
-      rawMessage: text.slice(0, 500),
+      rawMessage: text.slice(0, SMS_CONTENT_MAX_LENGTH),
     };
   }
 
@@ -111,7 +113,7 @@ function parseWithRegex(text: string): BankNotification | null {
       depositorName: depositor,
       amount: parseInt(amountStr.replace(/,/g, '')),
       transactionTime: date ? parseDateTime(date) : undefined,
-      rawMessage: text.slice(0, 500),
+      rawMessage: text.slice(0, SMS_CONTENT_MAX_LENGTH),
     };
   }
 
@@ -125,7 +127,7 @@ function parseWithRegex(text: string): BankNotification | null {
       bankName: '알수없음',
       depositorName: genericMatch1[2],
       amount: parseInt(genericMatch1[1].replace(/,/g, '')),
-      rawMessage: text.slice(0, 500),
+      rawMessage: text.slice(0, SMS_CONTENT_MAX_LENGTH),
     };
   }
 
@@ -135,7 +137,7 @@ function parseWithRegex(text: string): BankNotification | null {
       bankName: '알수없음',
       depositorName: genericMatch2[1],
       amount: parseInt(genericMatch2[2].replace(/,/g, '')),
-      rawMessage: text.slice(0, 500),
+      rawMessage: text.slice(0, SMS_CONTENT_MAX_LENGTH),
     };
   }
 
@@ -149,7 +151,7 @@ async function parseWithAI(text: string, env: Env): Promise<BankNotification | n
 
 텍스트:
 """
-${text.slice(0, 500)}
+${text.slice(0, SMS_CONTENT_MAX_LENGTH)}
 """
 
 요구사항:
@@ -227,7 +229,7 @@ ${text.slice(0, 500)}
         depositorName: result.depositorName,
         amount: typeof result.amount === 'string' ? parseInt(result.amount.replace(/,/g, '')) : result.amount,
         transactionTime: result.transactionTime ? new Date(result.transactionTime) : undefined,
-        rawMessage: text.slice(0, 500),
+        rawMessage: text.slice(0, SMS_CONTENT_MAX_LENGTH),
       };
     }
   } catch (e) {
diff --git a/src/tools/deposit-tool.ts b/src/tools/deposit-tool.ts
index 6ccfb22..01624ca 100644
--- a/src/tools/deposit-tool.ts
+++ b/src/tools/deposit-tool.ts
@@ -10,6 +10,8 @@ import { createLogger, maskUserId } from '../utils/logger';
 
 const logger = createLogger('deposit-tool');
 
+const LOG_RESULT_MAX_LENGTH = 200;
+
 export const manageDepositTool = {
   type: 'function',
   function: {
@@ -206,7 +208,7 @@ export async function executeManageDeposit(
 
     logger.info('executeDepositFunction 호출', { funcName, funcArgs });
     const result = await executeDepositFunction(funcName, funcArgs, context);
-    logger.info('결과', { result: JSON.stringify(result).slice(0, 200) });
+    logger.info('결과', { result: JSON.stringify(result).slice(0, LOG_RESULT_MAX_LENGTH) });
 
     // 결과 포맷팅 (고정 형식)
     return formatDepositResult(action, result);