diff --git a/commands/arc.md b/commands/arc.md
index cb08848..290ebf1 100644
--- a/commands/arc.md
+++ b/commands/arc.md
@@ -56,6 +56,15 @@ ArcPhaseGate 控制 execution-plan.json 写入权限。phase 默认 `discussing`
 
 **推进方式**：用户说"确认"/"可以"/"同意"后，`ArcPhaseGate.confirm_architecture()` 自动推进。不丢失（已修复）。
 
+## 弱模型安全（INV-16）
+
+Do Worker 可能是廉价模型/本地小模型，字面理解任务无推断能力。产出每个任务时必须：
+
+1. **禁止歧义词** — 不用"清理"、"重构"、"优化"等宽泛动词，指明具体改什么
+2. **否定约束显式化** — 写明**不做什么**（如"不删除 src/ 下现有模块"）
+3. **文件范围精确化** — `files_dirs` 精确到文件级，不写 `src/` 目录级
+4. **完成标准可验证** — `done_when` 能用 `grep`/`diff`/`cmake --build` 客观验证
+
 ## Logging Standard
 
 When planning C++ projects, the first task MUST be "integrate spdlog" if not already present. All generated code must use spdlog, not std::cout/qDebug/printf.
\ No newline at end of file
diff --git a/lib/air_runtime/modes/arc_mode.py b/lib/air_runtime/modes/arc_mode.py
index c926249..6d710db 100644
--- a/lib/air_runtime/modes/arc_mode.py
+++ b/lib/air_runtime/modes/arc_mode.py
@@ -21,6 +21,30 @@ from air_runtime.paths import event_log_path
 from air_runtime.utils import ordered_unique
 
 
+# INV-16: 弱模型安全 — 危险词列表
+DANGEROUS_TASK_WORDS = [
+    "清理", "清除", "删除所有", "重构整个", "重写全部",
+    "clear", "delete all", "remove all", "rewrite entire", "refactor whole",
+]
+DIR_LEVEL_FILE_SCOPE_PATTERNS = [
+    "src/", "lib/", "include/", "tests/", "modules/",
+]
+
+def _audit_task_safety(task_id: str, task_text: str, files_dirs: str, done_when: str) -> list[str]:
+    """INV-16: 扫描单个任务的危险词和宽泛文件范围，返回警告列表。"""
+    warnings = []
+    text_lower = task_text.lower()
+    for word in DANGEROUS_TASK_WORDS:
+        if word.lower() in text_lower:
+            warnings.append(f"[{task_id}] 含危险词 '{word}' — 建议改为精确描述（如'修改 CMakeLists.txt 去掉 sipclient 依赖'而非'清理{word}'）")
+    for pattern in DIR_LEVEL_FILE_SCOPE_PATTERNS:
+        if pattern in files_dirs and not any(f.endswith(ext) for ext in [".cpp", ".hpp", ".h", ".py", ".ts", ".md", ".json", ".txt", ".cmake"] for f in files_dirs.split(",")):
+            if not done_when or "不" not in done_when:
+                warnings.append(f"[{task_id}] 文件范围含目录级 '{pattern}' 但 done_when 无否定约束 — Worker 可能误解文件范围")
+            break
+    return warnings
+
+
 class ArcPhaseGate:
     """三阶段门控：discussing → proposing → confirmed。
     execution-plan.json 仅在 phase=confirmed 时允许写入。
@@ -219,6 +243,14 @@ def parallel_review_mode(project_root: Path, todo_path: Path) -> dict:
         graph.add_edge(Edge(source=edge_info["source"], target=edge_info["target"],
                            kind=edge_info.get("kind", "dependency")))
 
+    # INV-16: 弱模型安全审计 — 扫描所有 TODO 任务的危险词和宽泛文件范围
+    safety_warnings = []
+    for nid, node in graph.nodes.items():
+        if node.status == "TODO":
+            safety_warnings.extend(
+                _audit_task_safety(nid, node.task, node.files_dirs, node.done_when)
+            )
+
     _export_task_graph_json(graph, paths["task_graph_json"])
 
     # 生成执行计划
@@ -233,6 +265,7 @@ def parallel_review_mode(project_root: Path, todo_path: Path) -> dict:
         "serializationPoints": review.serialization_points,
         "doneWhenViolations": done_when_violations,  # P1-19.1: Done When 不含"测试通过"的任务
         "boundaryTestTasks": [n.id for n in graph.nodes.values() if n.test_required],
+        "safetyWarnings": safety_warnings,  # INV-16: 弱模型安全警告
     }
     atomic_json_write(paths["execution_plan_json"], execution_plan)
 
diff --git a/skills/airplan/SKILL.md b/skills/airplan/SKILL.md
index 86e5ae1..70fef1e 100644
--- a/skills/airplan/SKILL.md
+++ b/skills/airplan/SKILL.md
@@ -98,6 +98,13 @@ AirDo 处理 UI 任务时必须使用 frontend-design Skill：
 - 自动 git revert 已合并的旧代码
 - AirRvr 终审检查 INVALIDATED 任务代码是否已清理
 
+### INV-16 弱模型安全任务描述
+AirArc 产出任务时，假设 Do Worker 是**廉价模型/本地小模型**，字面理解任务无推断能力：
+- **禁止歧义词**：禁止"清理"、"重构"、"优化"等宽泛动词，必须指明具体改什么文件、改什么内容
+- **否定约束显式化**：任务必须写明**不做什么**（如"不删除 src/ 下现有模块文件"、"不修改 CMakeLists.txt 中已有 target"）
+- **文件范围精确化**：`files_dirs` 不能写 `src/` 这种目录级范围，必须精确到具体文件
+- **完成标准可验证**：`done_when` 必须能用 `grep`/`diff`/`cmake --build` 等命令客观验证，不含主观判断
+
 ## L1 代码级保障（不依赖 LLM 自觉）
 
 以下功能由引擎代码强制执行，SKILL.md 指令仅作辅助：