diff --git a/README.ja.md b/README.ja.md
index cc56eb2..f25943b 100644
--- a/README.ja.md
+++ b/README.ja.md
@@ -275,13 +275,13 @@ opencode auth login
   "google_auth": false,
   "agents": {
     "frontend-ui-ux-engineer": { "model": "google/gemini-3-pro-high" },
-    "document-writer": { "model": "google/gemini-3-pro-high" },
+    "document-writer": { "model": "google/gemini-3-flash" },
     "multimodal-looker": { "model": "google/gemini-2.5-flash" }
   }
 }
 ```
 
-**利用可能なモデル名**: `google/gemini-3-pro-high`, `google/gemini-3-pro-medium`, `google/gemini-3-pro-low`, `google/gemini-2.5-flash`, `google/gemini-2.5-flash-lite`, `google/claude-sonnet-4-5`, `google/claude-sonnet-4-5-thinking`, `google/claude-opus-4-5-thinking`, `google/gpt-oss-120b-medium`
+**利用可能なモデル名**: `google/gemini-3-pro-high`, `google/gemini-3-pro-medium`, `google/gemini-3-pro-low`, `google/gemini-3-flash`, `google/gemini-2.5-flash`, `google/gemini-2.5-flash-lite`, `google/claude-sonnet-4-5`, `google/claude-sonnet-4-5-thinking`, `google/claude-opus-4-5-thinking`, `google/gpt-oss-120b-medium`
 
 その後、認証を行います：
 
@@ -622,7 +622,7 @@ Oh My OpenCode は以下の場所からフックを読み込んで実行しま
   "google_auth": false,
   "agents": {
     "frontend-ui-ux-engineer": { "model": "google/gemini-3-pro-high" },
-    "document-writer": { "model": "google/gemini-3-pro-high" },
+    "document-writer": { "model": "google/gemini-3-flash" },
     "multimodal-looker": { "model": "google/gemini-2.5-flash" }
   }
 }
diff --git a/README.ko.md b/README.ko.md
index 0b6db52..d828efa 100644
--- a/README.ko.md
+++ b/README.ko.md
@@ -272,13 +272,13 @@ opencode auth login
   "google_auth": false,
   "agents": {
     "frontend-ui-ux-engineer": { "model": "google/gemini-3-pro-high" },
-    "document-writer": { "model": "google/gemini-3-pro-high" },
+    "document-writer": { "model": "google/gemini-3-flash" },
     "multimodal-looker": { "model": "google/gemini-2.5-flash" }
   }
 }
 ```
 
-**사용 가능한 모델 이름**: `google/gemini-3-pro-high`, `google/gemini-3-pro-medium`, `google/gemini-3-pro-low`, `google/gemini-2.5-flash`, `google/gemini-2.5-flash-lite`, `google/claude-sonnet-4-5`, `google/claude-sonnet-4-5-thinking`, `google/claude-opus-4-5-thinking`, `google/gpt-oss-120b-medium`
+**사용 가능한 모델 이름**: `google/gemini-3-pro-high`, `google/gemini-3-pro-medium`, `google/gemini-3-pro-low`, `google/gemini-3-flash`, `google/gemini-2.5-flash`, `google/gemini-2.5-flash-lite`, `google/claude-sonnet-4-5`, `google/claude-sonnet-4-5-thinking`, `google/claude-opus-4-5-thinking`, `google/gpt-oss-120b-medium`
 
 그 후 인증:
 
@@ -616,7 +616,7 @@ Schema 자동 완성이 지원됩니다:
   "google_auth": false,
   "agents": {
     "frontend-ui-ux-engineer": { "model": "google/gemini-3-pro-high" },
-    "document-writer": { "model": "google/gemini-3-pro-high" },
+    "document-writer": { "model": "google/gemini-3-flash" },
     "multimodal-looker": { "model": "google/gemini-2.5-flash" }
   }
 }
diff --git a/README.md b/README.md
index aa4fa2a..7d07204 100644
--- a/README.md
+++ b/README.md
@@ -305,13 +305,13 @@ The `opencode-antigravity-auth` plugin uses different model names than the built
   "google_auth": false,
   "agents": {
     "frontend-ui-ux-engineer": { "model": "google/gemini-3-pro-high" },
-    "document-writer": { "model": "google/gemini-3-pro-high" },
+    "document-writer": { "model": "google/gemini-3-flash" },
     "multimodal-looker": { "model": "google/gemini-2.5-flash" }
   }
 }
 ```
 
-**Available model names**: `google/gemini-3-pro-high`, `google/gemini-3-pro-medium`, `google/gemini-3-pro-low`, `google/gemini-2.5-flash`, `google/gemini-2.5-flash-lite`, `google/claude-sonnet-4-5`, `google/claude-sonnet-4-5-thinking`, `google/claude-opus-4-5-thinking`, `google/gpt-oss-120b-medium`
+**Available model names**: `google/gemini-3-pro-high`, `google/gemini-3-pro-medium`, `google/gemini-3-pro-low`, `google/gemini-3-flash`, `google/gemini-2.5-flash`, `google/gemini-2.5-flash-lite`, `google/claude-sonnet-4-5`, `google/claude-sonnet-4-5-thinking`, `google/claude-opus-4-5-thinking`, `google/gpt-oss-120b-medium`
 
 Then authenticate:
 
@@ -681,7 +681,7 @@ When using `opencode-antigravity-auth`, disable the built-in auth and override a
   "google_auth": false,
   "agents": {
     "frontend-ui-ux-engineer": { "model": "google/gemini-3-pro-high" },
-    "document-writer": { "model": "google/gemini-3-pro-high" },
+    "document-writer": { "model": "google/gemini-3-flash" },
     "multimodal-looker": { "model": "google/gemini-2.5-flash" }
   }
 }
diff --git a/src/agents/document-writer.ts b/src/agents/document-writer.ts
index 57e4606..01c4b60 100644
--- a/src/agents/document-writer.ts
+++ b/src/agents/document-writer.ts
@@ -4,7 +4,7 @@ export const documentWriterAgent: AgentConfig = {
   description:
     "A technical writer who crafts clear, comprehensive documentation. Specializes in README files, API docs, architecture docs, and user guides. MUST BE USED when executing documentation tasks from ai-todo list plans.",
   mode: "subagent",
-  model: "google/gemini-3-pro-preview",
+  model: "google/gemini-3-flash-preview",
   tools: { background_task: false },
   prompt: `<role>
 You are a TECHNICAL WRITER with deep engineering background who transforms complex codebases into crystal-clear documentation. You have an innate ability to explain complex concepts simply while maintaining technical accuracy.