diff --git a/Packages/com.shlifedev.floating-text-render-feature/Runtime/DefaultFloatingTextAnimator.cs b/Packages/com.shlifedev.floating-text-render-feature/Runtime/DefaultFloatingTextAnimator.cs
index b41862e..c34d0c0 100644
--- a/Packages/com.shlifedev.floating-text-render-feature/Runtime/DefaultFloatingTextAnimator.cs
+++ b/Packages/com.shlifedev.floating-text-render-feature/Runtime/DefaultFloatingTextAnimator.cs
@@ -37,6 +37,7 @@ public override void Evaluate(float elapsed, float duration,
                 : 1f - EaseInQuad(Mathf.Clamp01(alphaElapsed / fadeDuration));
         }
 
+        // FloatingTextAnimator.ScheduleEvaluateBatch must be overridden with a Burst-compatible batch path.
         public override JobHandle ScheduleEvaluateBatch(
             NativeArray<FloatingTextEntryNative> entries,
             NativeArray<AnimationResult> results)
diff --git a/Packages/com.shlifedev.floating-text-render-feature/Runtime/FloatingTextAnimator.cs b/Packages/com.shlifedev.floating-text-render-feature/Runtime/FloatingTextAnimator.cs
index 8727833..86cfd4e 100644
--- a/Packages/com.shlifedev.floating-text-render-feature/Runtime/FloatingTextAnimator.cs
+++ b/Packages/com.shlifedev.floating-text-render-feature/Runtime/FloatingTextAnimator.cs
@@ -1,6 +1,9 @@
 using Unity.Collections;
 using Unity.Jobs;
 using UnityEngine;
+#if UNITY_ASSERTIONS
+using UnityEngine.Assertions;
+#endif
 
 namespace LD.FloatingTextRenderFeature
 {
@@ -10,6 +13,10 @@ namespace LD.FloatingTextRenderFeature
     /// </summary>
     public abstract class FloatingTextAnimator : ScriptableObject
     {
+#if DEVELOPMENT_BUILD || UNITY_EDITOR
+        private static bool s_loggedManagedFallbackWarning;
+#endif
+
         /// <summary>
         /// Evaluate animation values at the given time.
         /// </summary>
@@ -29,6 +36,22 @@ public virtual JobHandle ScheduleEvaluateBatch(
             NativeArray<FloatingTextEntryNative> entries,
             NativeArray<AnimationResult> results)
         {
+#if UNITY_ASSERTIONS
+            Assert.IsTrue(false,
+                $"[{nameof(FloatingTextAnimator)}] {GetType().Name} is using managed fallback in {nameof(ScheduleEvaluateBatch)}(). " +
+                "Override ScheduleEvaluateBatch() and provide a Burst-compatible job for production use.");
+#endif
+
+#if DEVELOPMENT_BUILD || UNITY_EDITOR
+            if (!s_loggedManagedFallbackWarning)
+            {
+                s_loggedManagedFallbackWarning = true;
+                Debug.LogWarning(
+                    $"[{nameof(FloatingTextAnimator)}] {GetType().Name} did not override {nameof(ScheduleEvaluateBatch)}(). " +
+                    "Falling back to managed Evaluate() loop. Implement a Burst job to avoid per-frame main-thread cost.");
+            }
+#endif
+
             for (int i = 0; i < entries.Length; i++)
             {
                 var e = entries[i];
diff --git a/Packages/com.shlifedev.floating-text-render-feature/Runtime/FloatingTextManager.cs b/Packages/com.shlifedev.floating-text-render-feature/Runtime/FloatingTextManager.cs
index 0290e20..5d7168c 100644
--- a/Packages/com.shlifedev.floating-text-render-feature/Runtime/FloatingTextManager.cs
+++ b/Packages/com.shlifedev.floating-text-render-feature/Runtime/FloatingTextManager.cs
@@ -6,6 +6,9 @@
 using Unity.Mathematics;
 using UnityEngine;
 using UnityEngine.AddressableAssets;
+#if UNITY_ASSERTIONS
+using UnityEngine.Assertions;
+#endif
 #if UNITY_EDITOR
 using UnityEditor;
 #endif
@@ -255,7 +258,10 @@ private void LateUpdate()
 
             EnsureDigitOutputCapacity(totalDigits);
 
-            // ── Phase 3: Evaluate animation (Burst job or managed fallback) ──
+            // ── Phase 3: Evaluate animation (custom animator must provide ScheduleEvaluateBatch Burst job) ──
+#if UNITY_ASSERTIONS
+            Assert.IsNotNull(_animator, $"[{nameof(FloatingTextManager)}] Animator is null.");
+#endif
             JobHandle animHandle = _animator.ScheduleEvaluateBatch(
                 _nativeEntries.GetSubArray(0, count),
                 _animResults.GetSubArray(0, count));
diff --git a/README.md b/README.md
index 4b0a491..36d190e 100644
--- a/README.md
+++ b/README.md
@@ -39,6 +39,18 @@ FloatingTextManager.Instance.Show(worldPosition, damage);
 FloatingTextManager.Instance.Show(worldPosition, damage, duration: 1.0f, scale: 1.5f);
 ```
 
+## 커스텀 Animator 작성 규칙
+
+`FloatingTextAnimator`를 상속해 커스텀 애니메이터를 만들 때는 아래 규칙을 지켜주세요.
+
+- `Evaluate(...)`는 단일 엔트리 계산 로직(수학식) 정의용입니다.
+- `ScheduleEvaluateBatch(...)`는 **반드시 override** 해서 `IJobFor`/`IJobParallelFor` 기반의 Burst job을 스케줄해야 합니다.
+- `FloatingTextManager`는 매 프레임 `_animator.ScheduleEvaluateBatch(...)`를 호출합니다.
+  - 미구현 시 managed fallback(`Evaluate` 루프)으로 진입하며, 개발 빌드/에디터에서는 경고 로그가 1회 출력됩니다.
+  - `UNITY_ASSERTIONS` 환경에서는 런타임 assert로 구현 누락을 빠르게 감지합니다.
+
+권장: 기본 구현은 `DefaultFloatingTextAnimator`의 `ScheduleEvaluateBatch` 예제를 참고하세요.
+
 ## Font Sprite Generator
 
 `Window > Floating Text > Font Sprite Generator` 메뉴에서 접근할 수 있는 에디터 도구입니다.