diff --git a/backend/common/models/gmodel.py b/backend/common/models/gmodel.py
index 36d3ab9..e59400a 100644
--- a/backend/common/models/gmodel.py
+++ b/backend/common/models/gmodel.py
@@ -15,9 +15,9 @@ class StructModel:
 class ErrorInfo(BaseModel, StructModel):
     """모든 응답에 공통으로 실리는 결과 정보. result.success / code / desc 로 내려간다."""
 
-    success: Optional[bool] = True
-    code: Optional[int] = ErrorType.SUCCESS.value
-    desc: Optional[str] = ErrorType.SUCCESS.name
+    success: Optional[bool] = Field(True, description="처리 성공 여부 (성공 시 true)")
+    code: Optional[int] = Field(ErrorType.SUCCESS.value, description="결과 코드 (ErrorType, 0=성공)")
+    desc: Optional[str] = Field(ErrorType.SUCCESS.name, description="결과 코드 이름 (ErrorType.name)")
 
     def SetResult(self, enum: ErrorType):
         if enum is not None:
@@ -41,8 +41,8 @@ class Req_WebPacketProtocol(WebPacketProtocol):
 
 class Res_WebPacketProtocol(WebPacketProtocol):
     # default_factory 로 인스턴스마다 새 ErrorInfo 를 생성한다 (mutable default 공유 방지).
-    result: ErrorInfo = Field(default_factory=ErrorInfo)
-    msg: Optional[str] = None
+    result: ErrorInfo = Field(default_factory=ErrorInfo, description="공통 처리 결과 (성공 여부/코드/설명)")
+    msg: Optional[str] = Field(None, description="부가 메시지 (선택)")
 
 
 class UserInfo(StructModel):
diff --git a/backend/router/router.py b/backend/router/router.py
index 57bd7e1..a249da6 100644
--- a/backend/router/router.py
+++ b/backend/router/router.py
@@ -50,7 +50,12 @@ async def log_time(request: Request, call_next):
     return response
 
 
-@app.get(path="/healthz", responses={404: {"description": "Not found"}})
+@app.get(
+    path="/healthz",
+    summary="헬스체크",
+    description="서버 기동 시각(API_SERVER_START_TIME)을 반환하는 헬스체크 엔드포인트.",
+    responses={404: {"description": "Not found"}},
+)
 async def healthz():
     return API_SERVER_START_TIME