diff --git a/tests/test_prune_tools.py b/tests/test_prune_tools.py
new file mode 100644
index 0000000..1f77c69
--- /dev/null
+++ b/tests/test_prune_tools.py
@@ -0,0 +1,115 @@
+"""
+测试：FC 工具去重 + 按场景动态裁剪（方案 A+B）。
+
+不依赖真实插件/引擎加载，用构造的 fake 数据验证：
+- mcp_to_openai_tools 按 name 去重（消除 cache + builtin 叠加重复）
+- prune_tools 分层裁剪：纯聊天极简、代码信号追加 lsp__*、外部 mcp 默认保留
+"""
+import pytest
+
+from xcli_core.fc_tools import mcp_to_openai_tools, prune_tools
+
+
+def _fc(name, desc="d"):
+    return {
+        "type": "function",
+        "function": {
+            "name": name,
+            "description": desc,
+            "parameters": {"type": "object", "properties": {}, "required": []},
+        },
+    }
+
+
+def _mcp(name, desc="d"):
+    """MCP 格式（get_mcp_tools 返回的就是这种）"""
+    return {
+        "name": name,
+        "description": desc,
+        "inputSchema": {"type": "object", "properties": {}, "required": []},
+    }
+
+
+class _FakePM:
+    """最小 plugin_manager：get_mcp_tools 返回预置列表。"""
+
+    def __init__(self, tools):
+        self._tools = tools
+
+    def get_mcp_tools(self):
+        return self._tools
+
+
+# ───────────── 去重 ─────────────
+
+def test_mcp_to_openai_tools_dedup():
+    # 模拟真实场景：cache 里已有 memory/scheduler，_get_builtin_tools 又追加一遍
+    pm = _FakePM([
+        _mcp("a"), _mcp("a"),                     # 同名重复
+        _mcp("b"),
+        _mcp("memory"), _mcp("scheduler"),        # cache 已有
+    ])
+    out = mcp_to_openai_tools(pm)
+    names = [t["function"]["name"] for t in out]
+    assert names.count("a") == 1, "同名工具应去重为 1"
+    assert names.count("memory") == 1, "builtin 与 cache 重复应去重"
+    assert names.count("scheduler") == 1
+    assert "b" in names
+    # builtin 追加的 memory/scheduler 不应再产生第二份
+    assert names.count("memory") == 1
+
+
+# ───────────── 分层裁剪 ─────────────
+
+_CORE = ["tool_search", "memory", "scheduler", "code_editor", "code_search",
+         "file_manager", "lsp__diagnostics", "lsp__hover", "lsp__definition",
+         "lsp__references", "lsp__completion", "browser_auto", "network_tools",
+         "ai_search", "git_tools", "cmd_executor", "sub_agent", "auto_engineer"]
+
+
+def _full_set():
+    return [_fc(n) for n in _CORE]
+
+
+def test_prune_pure_chat_keeps_only_always():
+    out = prune_tools(_full_set(), "你好啊，今天天气真不错")
+    names = {t["function"]["name"] for t in out}
+    assert names == {"tool_search", "memory", "scheduler"}, \
+        f"纯聊天应只留常驻工具，实际: {names}"
+
+
+def test_prune_code_signal_adds_lsp():
+    out = prune_tools(_full_set(), "帮我写一个 python 脚本读取文件")
+    names = {t["function"]["name"] for t in out}
+    assert "code_editor" in names
+    assert "file_manager" in names
+    assert "lsp__diagnostics" in names, "写代码应追加 pylsp 的 lsp__* 工具"
+    assert "lsp__completion" in names
+    assert "tool_search" in names
+
+
+def test_prune_git_signal():
+    out = prune_tools(_full_set(), "提交代码并查看 git 状态")
+    names = {t["function"]["name"] for t in out}
+    assert "git_tools" in names
+    assert "tool_search" in names
+
+
+def test_prune_external_mcp_kept_even_in_chat():
+    tools = [_fc("my_mcp__search"), _fc("code_editor"), _fc("tool_search")]
+    out = prune_tools(tools, "你好")
+    names = {t["function"]["name"] for t in out}
+    assert "my_mcp__search" in names, "外部桥接工具(mcp__)应默认保留"
+    assert "code_editor" not in names, "未命中信号的低频工具应被裁剪"
+    assert "tool_search" in names
+
+
+def test_prune_empty_input_no_crash():
+    out = prune_tools(_full_set(), "")
+    names = {t["function"]["name"] for t in out}
+    assert names == {"tool_search", "memory", "scheduler"}
+
+
+def test_prune_none_tools_returns_none():
+    assert prune_tools(None, "任意输入") is None
+    assert prune_tools([], "任意输入") == []
diff --git a/xcli_core/cli_core.py b/xcli_core/cli_core.py
index c8e125a..120c1dc 100644
--- a/xcli_core/cli_core.py
+++ b/xcli_core/cli_core.py
@@ -310,11 +310,14 @@ multi 操作支持一次修改多处：
                 plugins.append(tool)
 
         if plugins:
-            prompts.append("## 内置工具（使用 tool_search 查询详细用法）：")
-            for tool in plugins:
-                tool_name = tool.get('name', '')
-                tool_desc = tool.get('description', '')
-                prompts.append(f"- {tool_name}: {tool_desc}")
+            # 工具名清单（与 FC tools 字段互补；不逐条重复 description，避免双重曝光）。
+            # 无 function-calling 能力的模型只能靠此清单知道有哪些工具，故保留名称。
+            names = ", ".join(t.get('name', '') for t in plugins)
+            prompts.append(
+                "## 内置工具（已通过 function calling 的 tools 字段提供，调用前请先用 "
+                "tool_search 查询其详细用法与示例）\n"
+                f"工具名: {names}"
+            )
 
         if skills:
             prompts.append("\n## 扩展技能（已加载详细指令）：")
@@ -883,8 +886,8 @@ multi 操作支持一次修改多处：
             # TUI 模式也支持 FC
             fc_tools = None
             try:
-                from .fc_tools import mcp_to_openai_tools
-                fc_tools = mcp_to_openai_tools(self.liugin_manager)
+                from .fc_tools import mcp_to_openai_tools, prune_tools
+                fc_tools = prune_tools(mcp_to_openai_tools(self.liugin_manager), current_input)
             except Exception:
                 pass
             response = self.current_engine.generate_response(current_input, system_prompt=system_prompt, tools=fc_tools)
@@ -969,13 +972,11 @@ multi 操作支持一次修改多处：
                 if not self.current_engine:
                     response_result[0] = "错误: 当前没有可用的AI引擎，请检查ai_engines目录中的引擎插件"
                 else:
-                    # ── 收集 FC 工具定义 ──
+                    # ── 收集 FC 工具定义（按当前输入动态裁剪）──
                     fc_tools = None
                     try:
-                        from .fc_tools import mcp_to_openai_tools
-                        fc_tools = mcp_to_openai_tools(self.liugin_manager)
-                        if fc_tools:
-                            fc_tools = fc_tools  # 已经是列表
+                        from .fc_tools import mcp_to_openai_tools, prune_tools
+                        fc_tools = prune_tools(mcp_to_openai_tools(self.liugin_manager), current_input)
                     except Exception:
                         fc_tools = None
 
diff --git a/xcli_core/fc_tools.py b/xcli_core/fc_tools.py
index 1382e78..eebcc34 100644
--- a/xcli_core/fc_tools.py
+++ b/xcli_core/fc_tools.py
@@ -47,7 +47,117 @@ def mcp_to_openai_tools(plugin_manager) -> List[Dict]:
     builtin_tools = _get_builtin_tools()
     tools.extend(builtin_tools)
 
-    return tools
+    # ── 去重：同名工具只保留首个 ──
+    # 来源：get_mcp_tools() 的缓存里已含 memory/scheduler/lsp 等，
+    # 下方 _get_builtin_tools() 又追加了一遍，导致同名重复（约 17% 的 FC token 是垃圾）。
+    # 按 function.name 去重，消除双重曝光，对真实工具无影响。
+    seen = set()
+    deduped = []
+    for t in tools:
+        fname = (t.get("function") or {}).get("name", "")
+        if fname in seen:
+            continue
+        seen.add(fname)
+        deduped.append(t)
+    return deduped
+
+
+# ══════════════════════════════════════════════════════════════════
+#  动态工具裁剪（方案 B：按场景分层）
+#
+#  把 40+ 的 FC 工具全量发给模型，每轮要重发数千 token schema，且
+#  模型要在大列表里选对工具，决策面大、易选错、成本高。
+#  这里按「当前用户输入」的信号，只下发本轮相关的工具子集：
+#    - ALWAYS_KEEP：始终保留（含强制 tool_search 规则依赖、记忆、定时）
+#    - 外部桥接工具（含 "mcp__"）默认保留（用户显式配置，误杀代价高）
+#    - 命中关键词信号才追加对应工具（代码/文件/git/shell/浏览器/搜索/子agent/工程化）
+#  纯聊天时模型只背 ~10 个核心工具而非 40+，FC token 可降约 70%+。
+# ══════════════════════════════════════════════════════════════════
+
+# 始终保留的工具（与系统提示里的强制规则/记忆机制强绑定）
+ALWAYS_KEEP = {
+    "tool_search",   # 系统提示的「强制工具查询规则」依赖它
+    "memory",        # 持久化记忆
+    "scheduler",     # 定时任务
+}
+
+# 信号：关键词集合 → 追加「以此前缀开头」的工具
+_SIGNAL_RULES = [
+    # 代码 / 文件操作：Python 等源码信号命中时，连 pylsp 的 lsp__* 一起给
+    (
+        {"写", "创建", "新建", "修改", "编辑", "代码", "脚本", "函数", "bug", "修复",
+         "调试", "重构", "文件", "报错", "语法", "实现", "module", "def ", "import ",
+         "class ", "print(", ".py", ".js", ".ts", ".java", ".go", ".cpp", ".c", ".rs"},
+        ["code_editor", "code_search", "file_manager", "lsp__", "syntax_check", "check"],
+    ),
+    # 版本控制
+    (
+        {"git", "提交", "commit", "分支", "branch", "版本", "diff", "stash", "merge", "rebase"},
+        ["git_tools"],
+    ),
+    # Shell 命令
+    (
+        {"命令", "shell", "终端", "执行", "运行", "cmd", "bash", "powershell", "terminal"},
+        ["cmd_executor"],
+    ),
+    # 浏览器
+    (
+        {"浏览器", "网页", "点击", "browser", "打开网页", "截图", "scroll", "页面"},
+        ["browser_auto"],
+    ),
+    # 联网 / 搜索 / HTTP
+    (
+        {"搜索", "联网", "http", "请求", "url", "curl", "api", "查一下", "上网", "fetch"},
+        ["network_tools", "ai_search"],
+    ),
+    # 子 Agent 并行
+    (
+        {"子agent", "并行", "subagent", "sub_agent", "多智能体"},
+        ["sub_agent"],
+    ),
+    # 工程化自动化
+    (
+        {"测试", "test", "lint", "build", "自动化", "工程化", "ci", "部署", "deploy"},
+        ["auto_engineer"],
+    ),
+]
+
+
+def prune_tools(fc_tools: List[Dict], user_input: str) -> List[Dict]:
+    """
+    按当前用户输入动态裁剪 FC 工具子集。
+
+    返回保留下来的工具列表。无输入或空列表时原样返回（不裁剪）。
+    规则见模块顶部 _SIGNAL_RULES / ALWAYS_KEEP 注释。
+    """
+    if not fc_tools:
+        return fc_tools
+
+    text = (user_input or "").lower()
+
+    keep_prefixes = set()
+    for keywords, prefixes in _SIGNAL_RULES:
+        if any(kw in text for kw in keywords):
+            keep_prefixes.update(prefixes)
+
+    out = []
+    for t in fc_tools:
+        name = (t.get("function") or {}).get("name", "")
+        # 1) 常驻工具
+        if name in ALWAYS_KEEP:
+            out.append(t)
+            continue
+        # 2) 外部桥接工具（用户显式配置）默认保留，避免误杀
+        if "mcp__" in name:
+            out.append(t)
+            continue
+        # 3) 命中当前轮信号 → 追加（前缀匹配，如 lsp__diagnostics 命中 "lsp__"）
+        if any(name.startswith(p) for p in keep_prefixes):
+            out.append(t)
+            continue
+        # 4) 其余（未命中信号的低频工具）本轮裁剪掉
+
+    return out
 
 
 def _extract_fc_def(plugin) -> Optional[Dict]: