fix: separate Cua keyboard targeting and verify browser actions

plugins/cua-driver/RELEASE.md

@@ -1,8 +1,8 @@
-# Cua 电脑控制 0.36.0+artemis.1
+# Cua 电脑控制 0.36.0+artemis.2
 
-作为 ARTEMIS 插件市场的默认电脑控制实现，替代已下架的 Open Computer Use。此修订修复按应用名查找窗口时，被无效或冲突 PID 筛选为零窗口并误判浏览器不可用的问题；上游仍是固定的 Cua Driver 0.36.0 预发布版，市场标注开发预览。
+作为 ARTEMIS 插件市场的默认电脑控制实现，替代已下架的 Open Computer Use。此修订修复模型同时填写控件令牌与坐标，导致浏览器按键连续被拒绝的问题；上游仍是固定的 Cua Driver 0.36.0 预发布版，市场标注开发预览。
 
-修复内容：未知 PID 可省略或填 `null`；`0`、负数、非整数等无效 PID 明确拒绝。零窗口结果保留实际筛选条件，并给出同应用重新查找或检查最小化窗口的建议；去掉无关前台应用 PID 提示，不自动扩大查询范围或替用户选择其他应用。
+修复内容：`press_key` / `type_text` 只对目标窗口的当前焦点操作，不再暴露互斥的 element_token/x/y 参数；聚焦使用独立点击工具，控件赋值由必填 element_token 的 `set_value` 完成。`scroll` 仅按截图坐标定位滚动区域。旧格式在适配层返回明确未执行回执，不发送输入、不重新截图。补充浏览器前台输入与滚动后点击规则，不自动重试结果不确定的写操作。保留上一修订的应用名发现和无效 PID 修复。
 
 上游提交：`6d6c734c127025fb39ad5d585a10382808b39dc1`。Windows x64 原始 ZIP SHA256：`f8c47024b626f4e0e70f8428d2998df39e4879110c5722a29d5fd03e367353ad`。采用 MIT Driver，许可证随包提供；不包含 Cua Spaces、云环境或模型服务。
 

plugins/cua-driver/SKILL.md

@@ -4,10 +4,10 @@
 
 1. 先按应用名发现窗口，例如 `list_windows({"app":"Brave","on_screen_only":true})`；未知 `pid` 必须省略或填 `null`，不能填 `0`。`app` 与非空 `pid` 同时提供时会取交集，只有该应用实际返回的 PID 才能用于后续调用。空结果时先按 `lookup.suggested_arguments` 纠正筛选（去掉错误 PID 或检查最小化窗口），不能直接宣称浏览器不可用，也不能把无关前台进程号当成目标 PID。取得目标的 `pid`、`window_id` 后读取真实画面；只操作任务要求的窗口，不关闭其他应用。
 2. `get_window_state` 同时读取截图和 UIA 控件树。最新 `snapshot_id` 加 `:N` 即控件 `element_token`。优先用 `click` 点击最新控件；视觉目标用 `click_at`，坐标仅取本次截图上的窗口局部像素，不能用屏幕坐标，需携带本次 `capture_id`。两种点击参数互斥，不混用。
-3. 所有窗口操作明确传 `pid`、`window_id`。`set_value` 适合直接设置输入框；不支持时可明确聚焦后 `type_text`。观察控件支持的动作，不猜元素编号。`press_key` 传单键及 `modifiers` 数组。
+3. 所有窗口操作明确传 `pid`、`window_id`。`set_value` 必须带最新 `element_token`，用于设置具有 set_value 动作的输入框；同名 Text 标签不能当成 Edit 输入框。`press_key` 和 `type_text` 只操作当前焦点，不能传 `element_token`、`x`、`y`（也不要补 0/null）。需要聚焦控件时先 `click` / `click_at`，再输入。`press_key` 传单键及 `modifiers` 数组。
 4. 每个动作后插件自动返回一次新截图和控件树，新 snapshot 替换旧 token。接着用新 token，无需重复获取相同状态。仅当画面确实还在变化或需要核验时再次观察。一次调用只执行一次动作，超时不自动重发。
-5. 默认后台操作。`effect=unverifiable/suspected_noop` 仅代表投递/效果未确认，必须检查返回画面和读回值；`refused` 是未执行。后台无效时，可在任务授权范围内显式 `delivery_mode=foreground` 后再次检查。不要仅凭工具成功声称测试通过。
-6. `scroll` 需要最新窗口/滚动区域，使用 up/down/left/right、amount、by=line/page；先观察是否真的滚动。`get_window_state(since="latest")` 可在同一窗口读取差异，但新 snapshot_id 仍替换旧 token。
+5. 默认后台操作；Brave/Chrome/Edge 等 Chromium 浏览器的点击（尤其滚动后）、快捷键、文字输入和滚动直接使用 `delivery_mode=foreground`。例如新标签页：`press_key(key="t",modifiers=["ctrl"],delivery_mode="foreground")`；地址导航：Ctrl+L → `type_text(text=网址,delivery_mode="foreground")` → Enter，各调用均带同一目标 pid/window_id。检查新页面再继续。`effect=unverifiable/suspected_noop` 仅代表投递/效果未确认，必须检查返回画面和读回值；`refused` 是未执行。其他应用后台无效时，可在任务授权范围内显式 foreground 后再次检查。不要仅凭工具成功声称测试通过。
+6. `scroll` 必须带最新截图中滚动区域内的 `x,y`，不能传 `element_token`。使用 up/down/left/right、amount、by=line/page；滚轮刻度不保证固定像素或整页距离，根据返回画面确认实际位移再继续。`get_window_state(since="latest")` 可在同一窗口读取差异，但新 snapshot_id 仍替换旧 token。
 7. `save_screenshot` 保存最新窗口 PNG 到当前任务 trace，filename 仅是文件名，不能传路径，不覆盖已有文件。实际成功返回 SHA256 和附件；不得把工具内存截图当成已保存文件。
 
 不提供 Cua 自带调度、录屏、回放、配置修改、安装器、任意脚本或自动升级接口。浏览器本轮使用窗口视觉/UIA 通路；未接入 DOM 或已有登录浏览器调试权限。此包基于上游 0.36.0 预发布版，通过已列出的本机验证，其他场景的支持范围以 VERIFICATION.md 为准。

plugins/cua-driver/VERIFICATION.md

@@ -50,3 +50,13 @@ Cua 第三轮虽然独立验收通过，ARTEMIS 最终核验却没有生成结
 新增 Go 回归覆盖无效 PID 在调用驱动前拒绝、null 省略、冲突筛选保持原范围并提示同应用重查、可见窗口为空时保留目标检查最小化窗口，以及驱动错误不得伪装成空列表。`tests/cua_discovery_smoke.py` 对已打开的指定应用只读验证主机 schema、适配器、应用名发现、null PID、冲突 PID 恢复，以及实际截图和 UIA 树；不点击、不导航、不修改用户页面。
 
 本修订实测通过：真实 Brave 应用名枚举、null PID、省略 PID、冲突 PID 后按建议恢复，并取得真实截图及 UIA 树。原生窗口表单、34 像素目标、滚动、PNG 附件校验和窗口录像回归通过；Go 测试、vet 与 Python Ruff 检查通过。未重跑原业务的整段移动端/PC布局验收，不将窗口发现修复等同于原任务通过。
+
+## 输入参数修订 0.36.0+artemis.2
+
+任务 f1928dc9 的窗口发现、截图和 UIA 树已经成功，但后续三次 Ctrl+T 同时传 element_token 与 x/y，上游在执行前拒绝，未完成导航。旧适配层把此错误归为不确定并刷新截图，产生新 token 后仍重复相同冲突。
+
+修订在工具 schema 中分开聚焦和键盘输入：按键/打字只接受窗口当前焦点，set_value 必须指定控件，scroll 仅接受成对坐标。Go 回归覆盖真实冲突参数（包括 x=0,y=0）、明确 not_started/none 回执，以及在接触 HWND/驱动前拒绝，不自动重试写动作。
+
+`tests/cua_browser_smoke.py` 新增独立 Brave profile 和本地表单，全部操作经过打包后的 Cua MCP，未使用 CDP/DOM 控制。实测通过 Ctrl+T 新建标签、Ctrl+L 地址栏导航、UIA set_value、聚焦后的中文 type_text、表单恰好提交一次并读回、实际滚动位移、底部按钮及 PNG SHA256。测试窗口退出，不操作用户原有标签页。
+
+实测还发现 Chromium 后台点击可能沿用滚动前的控件位置；前台路径会解析可见位置，已验证滚动后点击成功，schema/Skill 明确要求浏览器使用 foreground。滚轮 amount/by 不是精确滚动像素或页数，测试按页面滚动事件决定是否继续。不能据小样本宣称所有浏览器、DPI、跨端业务都通过；原业务完整任务未重跑，移动端问题不在本修订范围。

plugins/cua-driver/main.go

@@ -25,7 +25,7 @@ import (
 //go:embed tools.json
 var toolsJSON []byte
 
-const adapterVersion = "0.36.0+artemis.1"
+const adapterVersion = "0.36.0+artemis.2"
 
 type obj = map[string]any
 type request struct {
@@ -191,6 +191,13 @@ func (a *adapter) validate(name string, args obj) error {
 	if !ok {
 		return errors.New("tool is not exposed")
 	}
+	if name == "press_key" || name == "type_text" {
+		for _, key := range []string{"element_token", "x", "y"} {
+			if _, supplied := args[key]; supplied {
+				return errors.New(name + " uses the window's current focus; omit element_token/x/y. Focus with click/click_at first, or use set_value for a UIA field")
+			}
+		}
+	}
 	props := object(schema["properties"])
 	for key := range args {
 		if _, ok := props[key]; !ok {
@@ -209,6 +216,9 @@ func (a *adapter) validate(name string, args obj) error {
 	if num(args["pid"]) <= 0 || num(args["window_id"]) <= 0 {
 		return errors.New("a concrete pid and window_id are required")
 	}
+	if name == "set_value" && strings.TrimSpace(str(args["element_token"])) == "" {
+		return errors.New("set_value requires the latest element_token; use type_text for the current focus")
+	}
 	if name == "save_screenshot" && !validFilename(str(args["filename"])) {
 		return errors.New("filename must be a new plain PNG filename")
 	}

plugins/cua-driver/main_test.go

@@ -59,3 +59,69 @@ func TestClickModesAreDisjoint(t *testing.T) {
 		t.Fatal("pixel action lacks capture")
 	}
 }
+
+func TestKeyboardRejectsAmbiguousTargetsBeforeWindowOrDriverAccess(t *testing.T) {
+	a := newAdapter(nil) // Any upstream access would panic.
+	for _, name := range []string{"press_key", "type_text"} {
+		for _, extra := range []obj{
+			{"element_token": "s00000001:9", "x": 576, "y": 25},
+			{"element_token": "s00000002:9", "x": 0, "y": 0},
+			{"x": 0, "y": 0}, {"element_token": nil},
+		} {
+			args := obj{"pid": 1, "window_id": 2}
+			if name == "press_key" {
+				args["key"] = "t"
+				args["modifiers"] = []any{"ctrl"}
+			} else {
+				args["text"] = "test"
+			}
+			for k, v := range extra {
+				args[k] = v
+			}
+			r := a.handle(name, args)
+			rec := object(object(r["structuredContent"])["artemis"])
+			if r["isError"] != true || rec["execution"] != "not_started" || rec["side_effect"] != "none" || rec["error_code"] != "invalid_input" {
+				t.Fatalf("%s ambiguous action was not rejected before delivery: %v", name, r)
+			}
+		}
+	}
+}
+
+func TestInputContractsHaveOneTargetingMode(t *testing.T) {
+	a := newAdapter(nil)
+	for _, name := range []string{"press_key", "type_text"} {
+		props := object(a.schemas[name]["properties"])
+		for _, key := range []string{"element_token", "x", "y"} {
+			if _, exists := props[key]; exists {
+				t.Fatalf("%s exposes ambiguous %s", name, key)
+			}
+		}
+	}
+	for name, args := range map[string]obj{
+		"press_key": {"pid": 1, "window_id": 2, "key": "t", "modifiers": []any{"ctrl"}, "delivery_mode": "foreground"},
+		"type_text": {"pid": 1, "window_id": 2, "text": "中文"},
+		"set_value": {"pid": 1, "window_id": 2, "element_token": "s00000001:9", "value": "value"},
+		"scroll":    {"pid": 1, "window_id": 2, "direction": "down", "x": 100, "y": 100},
+	} {
+		if err := a.validate(name, args); err != nil {
+			t.Fatalf("valid %s: %v", name, err)
+		}
+	}
+	for _, token := range []any{nil, "", " "} {
+		if a.validate("set_value", obj{"pid": 1, "window_id": 2, "value": "v", "element_token": token}) == nil {
+			t.Fatal("set_value must target a concrete element")
+		}
+	}
+	if a.validate("set_value", obj{"pid": 1, "window_id": 2, "value": "v"}) == nil {
+		t.Fatal("set_value requires an element")
+	}
+	for _, extra := range []obj{{"x": 1}, {"x": 1, "y": 1, "element_token": "s00000001:9"}} {
+		args := obj{"pid": 1, "window_id": 2, "direction": "down"}
+		for k, v := range extra {
+			args[k] = v
+		}
+		if a.validate("scroll", args) == nil {
+			t.Fatal("ambiguous scroll accepted")
+		}
+	}
+}

plugins/cua-driver/plugin.json

@@ -2,7 +2,7 @@
   "schema_version": 2,
   "id": "cua-driver",
   "name": "电脑控制 · Cua",
-  "version": "0.36.0+artemis.1",
+  "version": "0.36.0+artemis.2",
   "description": "通过 Cua Driver 的窗口截图与可访问性树操作 Windows 应用及浏览器窗口；复用 ARTEMIS 的任务调度、步骤证据与录像。",
   "artemis_version": ">=2.0.0,<3.0.0",
   "platforms": [

plugins/cua-driver/tools.json

@@ -63,7 +63,7 @@
           "type": "string"
         },
         "window_id": {
-          "description": "HWND of the target window. Must belong to `pid`. Enumerate via `list_windows` or read from `launch_app`'s `windows` array.",
+          "description": "Exact HWND returned for this application by list_windows. Required and must belong to pid.",
           "type": "integer"
         }
       },
@@ -197,7 +197,7 @@
           "type": "integer"
         },
         "window_id": {
-          "description": "Exact native window identifier.",
+          "description": "Exact HWND returned for this application by list_windows. Required and must belong to pid.",
           "type": "integer"
         }
       },
@@ -215,7 +215,7 @@
   },
   {
     "name": "click",
-    "description": "Click the latest UIA element_token. This tool has no pixel coordinates. For visual targets use click_at. Returns effect and fresh observation; old tokens become stale.",
+    "description": "Click the latest UIA element_token. This tool has no pixel coordinates. For visual targets use click_at. Returns effect and fresh observation; old tokens become stale. For Chromium/Brave use foreground, especially after scrolling: it resolves off-screen element bounds before input. Background posted clicks may use old/off-screen positions; inspect actual evidence before retrying.",
     "inputSchema": {
       "additionalProperties": false,
       "properties": {
@@ -235,7 +235,7 @@
           "type": "integer"
         },
         "delivery_mode": {
-          "description": "Input delivery mode. 'background' (default) never swaps foreground: it routes through UIA Invoke / PostMessage and the window is never raised. For targets whose input stack silently drops posted events (Chromium/Electron content, GTK button",
+          "description": "background (default) avoids raising the window; unsupported input is refused. Use foreground for Chromium/Brave keyboard input and scrolling within task scope. Inspect the returned state before retrying an uncertain action.",
           "enum": [
             "background",
             "foreground"
@@ -252,7 +252,7 @@
           "type": "integer"
         },
         "window_id": {
-          "description": "HWND of the target window. Omit when element_token is supplied (the token carries it).",
+          "description": "Exact HWND returned for this application by list_windows. Required and must belong to pid.",
           "type": "integer"
         }
       },
@@ -275,7 +275,7 @@
       "additionalProperties": false,
       "properties": {
         "delivery_mode": {
-          "description": "Input delivery mode. 'background' (default) never swaps foreground: it routes through UIA Invoke / PostMessage and the window is never raised. For targets whose input stack silently drops posted events (Chromium/Electron content, GTK button",
+          "description": "background (default) avoids raising the window; unsupported input is refused. Use foreground for Chromium/Brave keyboard input and scrolling within task scope. Inspect the returned state before retrying an uncertain action.",
           "enum": [
             "background",
             "foreground"
@@ -309,7 +309,7 @@
           "type": "number"
         },
         "window_id": {
-          "description": "Target window handle (HWND). Optional — driver picks frontmost window of pid when omitted.",
+          "description": "Exact HWND returned for this application by list_windows. Required and must belong to pid.",
           "type": "integer"
         }
       },
@@ -330,23 +330,18 @@
   },
   {
     "name": "type_text",
-    "description": "Type text into the focused target window or specified latest element. Fresh observation follows. If background is unsupported, explicitly choose foreground within task scope.",
+    "description": "Type text at the current focus in the exact window. No element_token or coordinates. Focus a field with click/click_at or the address bar with Ctrl+L first; use set_value for direct UIA replacement. Chromium/Brave input requires foreground. Fresh observation follows.",
     "inputSchema": {
       "additionalProperties": false,
       "properties": {
         "delivery_mode": {
-          "description": "Input delivery mode. 'background' (default) never swaps foreground: it routes through UIA Invoke / PostMessage and the window is never raised. For targets whose input stack silently drops posted events (Chromium/Electron content, GTK button",
+          "description": "background (default) avoids raising the window; unsupported input is refused. Use foreground for Chromium/Brave keyboard input and scrolling within task scope. Inspect the returned state before retrying an uncertain action.",
           "enum": [
             "background",
             "foreground"
           ],
           "type": "string"
         },
-        "element_token": {
-          "description": "Opaque element handle from get_window_state. When supplied, type_text writes through UIA ValuePattern and reads that exact element back by handle. The shared ActionResult is confirmed only when the complete expected value is synchronously v",
-          "pattern": "^s[0-9a-f]{8}:[0-9]+$",
-          "type": "string"
-        },
         "pid": {
           "description": "Positive process ID returned for the target app by list_windows; never guess or use another app foreground PID.",
           "type": "integer"
@@ -356,16 +351,8 @@
           "type": "string"
         },
         "window_id": {
-          "description": "HWND of the target window. Omit when element_token is supplied (the token carries it).",
+          "description": "Exact HWND returned for this application by list_windows. Required and must belong to pid.",
           "type": "integer"
-        },
-        "x": {
-          "description": "Window-local screenshot-pixel X of the field to type into — the element px action form. Pass x,y (no element_token) and the tool pixel-clicks there to establish real renderer focus, then types. Use for Chromium/Electron inputs the UIA/WM_CH",
-          "type": "number"
-        },
-        "y": {
-          "description": "Window-local screenshot-pixel Y of the field (see x).",
-          "type": "number"
         }
       },
       "required": [
@@ -382,23 +369,18 @@
   },
   {
     "name": "press_key",
-    "description": "Send key and modifiers to the exact window, optionally focus element_token or x/y first. Fresh observation follows.",
+    "description": "Send a key and modifiers to the exact window current focus. No element_token or coordinates. For browser shortcuts (Ctrl+T, Ctrl+L, Enter), use foreground. To target a field, focus it with click/click_at first. Fresh observation follows; inspect before repeating.",
     "inputSchema": {
       "additionalProperties": false,
       "properties": {
         "delivery_mode": {
-          "description": "Input delivery mode. 'background' (default) never swaps foreground: it routes through UIA Invoke / PostMessage and the window is never raised. For targets whose input stack silently drops posted events (Chromium/Electron content, GTK button",
+          "description": "background (default) avoids raising the window; unsupported input is refused. Use foreground for Chromium/Brave keyboard input and scrolling within task scope. Inspect the returned state before retrying an uncertain action.",
           "enum": [
             "background",
             "foreground"
           ],
           "type": "string"
         },
-        "element_token": {
-          "description": "Element handle `<snapshot_id>:<row>` from get_window_state: row `[11]` of a read whose snapshot_id is s0000002a is \"s0000002a:11\" (also in `structuredContent.elements[].element_token`). Returns an explicit stale error naming the current sna",
-          "pattern": "^s[0-9a-f]{8}:[0-9]+$",
-          "type": "string"
-        },
         "key": {
           "description": "Key name (return, tab, escape, up, down, left, right, space, delete, home, end, pageup, pagedown, f1-f12, letter, digit).",
           "type": "string"
@@ -415,16 +397,8 @@
           "type": "integer"
         },
         "window_id": {
-          "description": "HWND for the target window. Omit when element_token is supplied; otherwise auto-resolves the pid's first visible window.",
+          "description": "Exact HWND returned for this application by list_windows. Required and must belong to pid.",
           "type": "integer"
-        },
-        "x": {
-          "description": "Window-local screenshot-pixel X — the element px action form: pixel-click there to focus, then send the key. Use when the key must go to a Chromium/Electron surface the UIA path can't focus. Pass with y, no element_token.",
-          "type": "number"
-        },
-        "y": {
-          "description": "Window-local screenshot-pixel Y (see x).",
-          "type": "number"
         }
       },
       "required": [
@@ -446,7 +420,7 @@
       "additionalProperties": false,
       "properties": {
         "delivery_mode": {
-          "description": "Input delivery mode. 'background' (default) never swaps foreground: it routes through UIA Invoke / PostMessage and the window is never raised. For targets whose input stack silently drops posted events (Chromium/Electron content, GTK button",
+          "description": "background (default) avoids raising the window; unsupported input is refused. Use foreground for Chromium/Brave keyboard input and scrolling within task scope. Inspect the returned state before retrying an uncertain action.",
           "enum": [
             "background",
             "foreground"
@@ -467,14 +441,15 @@
           "type": "string"
         },
         "window_id": {
-          "description": "HWND of the window. Omit when element_token is supplied (the token carries it).",
+          "description": "Exact HWND returned for this application by list_windows. Required and must belong to pid.",
           "type": "integer"
         }
       },
       "required": [
         "pid",
         "window_id",
-        "value"
+        "value",
+        "element_token"
       ],
       "type": "object"
     },
@@ -485,7 +460,7 @@
   },
   {
     "name": "scroll",
-    "description": "Scroll the target window/element at x,y. amount=1..50, by=line/page. Verify content changed in fresh returned observation.",
+    "description": "Scroll at x,y in the latest window screenshot. No element_token. Use a point inside the intended scroll surface, amount=1..50, by=line/page. Chromium/Brave requires foreground. Verify actual content movement in the returned observation.",
     "inputSchema": {
       "additionalProperties": false,
       "properties": {
@@ -504,7 +479,7 @@
           "type": "string"
         },
         "delivery_mode": {
-          "description": "Input delivery mode. 'background' (default) never swaps foreground: it routes through UIA Invoke / PostMessage and the window is never raised. For targets whose input stack silently drops posted events (Chromium/Electron content, GTK button",
+          "description": "background (default) avoids raising the window; unsupported input is refused. Use foreground for Chromium/Brave keyboard input and scrolling within task scope. Inspect the returned state before retrying an uncertain action.",
           "enum": [
             "background",
             "foreground"
@@ -521,32 +496,29 @@
           ],
           "type": "string"
         },
-        "element_token": {
-          "description": "Element handle `<snapshot_id>:<row>` from get_window_state: row `[11]` of a read whose snapshot_id is s0000002a is \"s0000002a:11\" (also in `structuredContent.elements[].element_token`). Returns an explicit stale error naming the current sna",
-          "pattern": "^s[0-9a-f]{8}:[0-9]+$",
-          "type": "string"
-        },
         "pid": {
           "description": "Positive process ID returned for the target app by list_windows; never guess or use another app foreground PID.",
           "type": "integer"
         },
         "window_id": {
-          "description": "HWND of the target window. Omit when element_token is supplied; otherwise auto-resolves the pid's first visible window.",
+          "description": "Exact HWND returned for this application by list_windows. Required and must belong to pid.",
           "type": "integer"
         },
         "x": {
-          "description": "With pid/window_id: window-local screenshot X used to target a nested scroll surface in foreground mode. Without pid/window_id: screen-absolute X for desktop scope. Must be paired with y.",
+          "description": "X inside the scroll area in latest window-local screenshot pixels; never screen coordinates. Must be paired with the other coordinate.",
           "type": "number"
         },
         "y": {
-          "description": "With pid/window_id: window-local screenshot Y used to target a nested scroll surface in foreground mode. Without pid/window_id: screen-absolute Y for desktop scope. Must be paired with x.",
+          "description": "Y inside the scroll area in latest window-local screenshot pixels; never screen coordinates. Must be paired with the other coordinate.",
           "type": "number"
         }
       },
       "required": [
         "pid",
         "window_id",
-        "direction"
+        "direction",
+        "x",
+        "y"
       ],
       "type": "object"
     },
@@ -569,7 +541,8 @@
         },
         "window_id": {
           "type": "integer",
-          "minimum": 1
+          "minimum": 1,
+          "description": "Exact HWND returned for this application by list_windows. Required and must belong to pid."
         },
         "filename": {
           "type": "string"
@@ -613,7 +586,7 @@
           "type": "integer"
         },
         "delivery_mode": {
-          "description": "Input delivery mode. 'background' (default) never swaps foreground: it routes through UIA Invoke / PostMessage and the window is never raised. For targets whose input stack silently drops posted events (Chromium/Electron content, GTK button",
+          "description": "background (default) avoids raising the window; unsupported input is refused. Use foreground for Chromium/Brave keyboard input and scrolling within task scope. Inspect the returned state before retrying an uncertain action.",
           "enum": [
             "background",
             "foreground"
@@ -625,7 +598,7 @@
           "type": "integer"
         },
         "window_id": {
-          "description": "HWND of the target window. Omit when element_token is supplied (the token carries it).",
+          "description": "Exact HWND returned for this application by list_windows. Required and must belong to pid.",
           "type": "integer"
         },
         "x": {