diff --git a/README.md b/README.md
index da2fab2..03088d6 100644
--- a/README.md
+++ b/README.md
@@ -49,10 +49,10 @@ Choose between [OpenAI](https://developers.openai.com/) or [Anthropic](https://w
 
 | Provider  | Default Model     | Default PR Review Model | API Key             |
 | --------- | ----------------- | ----------------------- | ------------------- |
-| OpenAI    | `gpt-5.6-luna`    | `gpt-5.6-terra`         | `openai_api_key`    |
+| OpenAI    | `gpt-5.6-luna`    | `gpt-5.6-luna`          | `openai_api_key`    |
 | Anthropic | `claude-sonnet-5` | `claude-opus-5`         | `anthropic_api_key` |
 
-The provider is auto-detected based on which API key you provide, and PR reviews default to a stronger model than the other AI features. Override with the `model` input, or use `review_model` to override PR review only.
+The provider is auto-detected based on which API key you provide. Override with the `model` input, or use `review_model` to override PR review only.
 
 ### 🛠️ How It Works
 
diff --git a/README.zh-CN.md b/README.zh-CN.md
index 812c4f0..7ef5dab 100644
--- a/README.zh-CN.md
+++ b/README.zh-CN.md
@@ -49,10 +49,10 @@
 
 | 提供商    | 默认模型          | 默认 PR Review 模型 | API Key             |
 | --------- | ----------------- | ------------------- | ------------------- |
-| OpenAI    | `gpt-5.6-luna`    | `gpt-5.6-terra`     | `openai_api_key`    |
+| OpenAI    | `gpt-5.6-luna`    | `gpt-5.6-luna`      | `openai_api_key`    |
 | Anthropic | `claude-sonnet-5` | `claude-opus-5`     | `anthropic_api_key` |
 
-提供商会根据提供的 API key 自动检测，PR review 默认使用比其他 AI 功能更强的模型。可通过 `model` 输入覆盖默认模型，也可使用 `review_model` 仅覆盖 PR review 模型。
+提供商会根据提供的 API key 自动检测。可通过 `model` 输入覆盖默认模型，也可使用 `review_model` 仅覆盖 PR review 模型。
 
 ### 🛠️ 工作方式
 
diff --git a/action.yml b/action.yml
index 92cc730..85c3ab1 100644
--- a/action.yml
+++ b/action.yml
@@ -79,7 +79,7 @@ inputs:
     description: "AI Model - defaults to gpt-5.6-luna or claude-sonnet-5 based on API key"
     required: false
   review_model:
-    description: "AI Model for PR reviews (optional, defaults to gpt-5.6-terra or claude-opus-5 based on API key)"
+    description: "AI Model for PR reviews (optional, defaults to gpt-5.6-luna or claude-opus-5 based on API key)"
     required: false
   first_issue_response:
     description: "Example response to a new issue"
diff --git a/actions/__init__.py b/actions/__init__.py
index 37c36ca..b289f9a 100644
--- a/actions/__init__.py
+++ b/actions/__init__.py
@@ -28,4 +28,4 @@
 #     ├── test_summarize_pr.py
 #     └── ...
 
-__version__ = "0.2.45"
+__version__ = "0.2.46"
diff --git a/actions/review_pr.py b/actions/review_pr.py
index 664bcfe..e7a79e6 100644
--- a/actions/review_pr.py
+++ b/actions/review_pr.py
@@ -546,7 +546,7 @@ def generate_pr_review(
             messages,
             text_format={"format": {"type": "json_schema", "name": "pr_review", "strict": True, "schema": schema}},
             model=review_model,
-            reasoning_effort="medium",
+            reasoning_effort="high",
             tools=tools,
             tool_handlers=tool_handlers,
             max_turns=MAX_AGENT_TURNS,
diff --git a/actions/utils/openai_utils.py b/actions/utils/openai_utils.py
index 0f6183b..b4135c5 100644
--- a/actions/utils/openai_utils.py
+++ b/actions/utils/openai_utils.py
@@ -24,7 +24,7 @@ WEB_SEARCH_CALL_COST = 0.01  # $10 per 1K calls
 # Default models (single source of truth)
 OPENAI_MODEL_DEFAULT = "gpt-5.6-luna"
 ANTHROPIC_MODEL_DEFAULT = "claude-sonnet-5"
-OPENAI_REVIEW_MODEL_DEFAULT = "gpt-5.6-terra"
+OPENAI_REVIEW_MODEL_DEFAULT = "gpt-5.6-luna"
 ANTHROPIC_REVIEW_MODEL_DEFAULT = "claude-opus-5"
 
 MODEL_COSTS = {  # (input, output) per 1M tokens
@@ -38,8 +38,8 @@ MODEL_COSTS = {  # (input, output) per 1M tokens
     "gpt-5.5": (5.00, 30.00),
     "gpt-5.4": (2.50, 15.00),
     "gpt-5.6-sol": (5.00, 30.00),
-    "gpt-5.6-terra": (2.50, 15.00),
-    "gpt-5.6-luna": (1.00, 6.00),
+    "gpt-5.6-terra": (2.00, 12.00),
+    "gpt-5.6-luna": (0.20, 1.20),
     "gpt-5-nano-2025-08-07": (0.05, 0.40),
     "gpt-5-mini-2025-08-07": (0.25, 2.00),
     # Anthropic Claude models
@@ -431,7 +431,7 @@ def get_agent_response(
         "context_management": [{"type": "compaction", "compact_threshold": 200_000}],
     }
     if "gpt-5" in model:
-        base_data["reasoning"] = {"effort": reasoning_effort or "low"}
+        base_data["reasoning"] = {"effort": reasoning_effort or "medium"}
     if text_format:
         base_data["text"] = text_format
 
@@ -578,7 +578,7 @@ def get_response(
             if background:
                 data["background"] = True
             if "gpt-5" in model:
-                data["reasoning"] = {"effort": reasoning_effort or "low"}
+                data["reasoning"] = {"effort": reasoning_effort or "medium"}
             if text_format:
                 data["text"] = text_format
             if tools:
diff --git a/tests/test_first_interaction.py b/tests/test_first_interaction.py
index cd43e8e..d985f5d 100644
--- a/tests/test_first_interaction.py
+++ b/tests/test_first_interaction.py
@@ -174,7 +174,7 @@ def test_generate_pr_review_uses_synchronous_response(mock_get_agent_response, m
     }
     assert kwargs["max_turns"] == review_pr.MAX_AGENT_TURNS
     assert kwargs["max_cost"] == review_pr.REVIEW_COST_SOFT_LIMIT
-    assert kwargs["reasoning_effort"] == "medium"
+    assert kwargs["reasoning_effort"] == "high"
     assert kwargs["request_timeout"] == (30, 120)
     assert "FULL FILE CONTENTS" not in mock_get_agent_response.call_args.args[0][1]["content"]
     assert (
diff --git a/tests/test_openai_utils.py b/tests/test_openai_utils.py
index fd4ae8b..46dd15b 100644
--- a/tests/test_openai_utils.py
+++ b/tests/test_openai_utils.py
@@ -24,7 +24,7 @@ from actions.utils.openai_utils import (
 def test_default_models():
     """Test canonical default models are priced so max_cost budgets stay enforceable."""
     assert OPENAI_MODEL_DEFAULT == "gpt-5.6-luna"
-    assert OPENAI_REVIEW_MODEL_DEFAULT == "gpt-5.6-terra"
+    assert OPENAI_REVIEW_MODEL_DEFAULT == "gpt-5.6-luna"
     assert ANTHROPIC_MODEL_DEFAULT == "claude-sonnet-5"
     assert ANTHROPIC_REVIEW_MODEL_DEFAULT == "claude-opus-5"
     for model in (
@@ -35,8 +35,8 @@ def test_default_models():
     ):
         assert model in MODEL_COSTS  # unpriced models disable max_cost budgets and misreport cost telemetry
     assert MODEL_COSTS["gpt-5.6-sol"] == (5.00, 30.00)
-    assert MODEL_COSTS["gpt-5.6-terra"] == (2.50, 15.00)
-    assert MODEL_COSTS["gpt-5.6-luna"] == (1.00, 6.00)
+    assert MODEL_COSTS["gpt-5.6-terra"] == (2.00, 12.00)
+    assert MODEL_COSTS["gpt-5.6-luna"] == (0.20, 1.20)
 
 
 def test_gpt_56_cost_includes_cache_write_and_long_context_rates():
@@ -52,8 +52,8 @@ def test_gpt_56_cost_includes_cache_write_and_long_context_rates():
     expected = ((272001 - 200 * 0.9 + 300 * 0.25) * 5.00 * 2 + 100 * 30.00 * 1.5) / 1e6
     assert _openai_usage_cost(usage, "gpt-5.6-sol") == expected
     turns = [{"input_tokens": 150000, "output_tokens": 0}] * 2
-    assert sum(_openai_usage_cost(turn, "gpt-5.6-luna") for turn in turns) == 0.3
-    assert _openai_usage_cost({"input_tokens": 300000, "output_tokens": 0}, "gpt-5.6-luna") == 0.6
+    assert sum(_openai_usage_cost(turn, "gpt-5.6-luna") for turn in turns) == 0.06
+    assert _openai_usage_cost({"input_tokens": 300000, "output_tokens": 0}, "gpt-5.6-luna") == 0.12
     old_model_expected = ((1000 - 200 * 0.9) * 5.00 + 100 * 30.00) / 1e6
     assert _openai_usage_cost({**usage, "input_tokens": 1000}, "gpt-5.5") == old_model_expected
 
@@ -292,7 +292,7 @@ def test_get_agent_response_calls_function_tools(mock_post):
     first_payload = mock_post.call_args_list[0].kwargs["json"]
     assert first_payload["store"] is True
     assert first_payload["service_tier"] == "default"
-    assert first_payload["reasoning"] == {"effort": "low"}
+    assert first_payload["reasoning"] == {"effort": "medium"}
     assert first_payload["context_management"] == [{"type": "compaction", "compact_threshold": 200_000}]
     assert first_payload["prompt_cache_key"].startswith("agent-run:")
     assert "include" not in first_payload