diff --git a/apps/ai-game-creator-shell/src-tauri/src/agent/direct_tool_bridge.rs b/apps/ai-game-creator-shell/src-tauri/src/agent/direct_tool_bridge.rs
index c006fed28..df52d77df 100644
--- a/apps/ai-game-creator-shell/src-tauri/src/agent/direct_tool_bridge.rs
+++ b/apps/ai-game-creator-shell/src-tauri/src/agent/direct_tool_bridge.rs
@@ -1245,7 +1245,8 @@ fn bridge_list_registered_assets(root: &Path, arguments: &Value) -> Value {
             "kind",
             DIRECT_TOOL_BRIDGE_MAX_RESOURCE_KIND_CHARS,
         )?
-        .map(|kind| GameCreationAppAssetKind::parse_with_context(&kind, "asset.list.kind"));
+        .map(|kind| bridge_asset_list_kind_filter(&kind))
+        .transpose()?;
         let asset_id = bridge_optional_bounded_string(
             arguments,
             "assetId",
@@ -1325,6 +1326,24 @@ fn bridge_list_registered_assets(root: &Path, arguments: &Value) -> Value {
     }
 }
 
+/// `asset.list` 的 `kind` 过滤：只接受 canonical 值，认不出的值直接报错。
+///
+/// 以前认不出的值会收口成 `unknown` 再参与等值过滤，结果是**静默返回空列表**：调用方（模型）
+/// 会以为项目里没有这类资产，而不是"你传的 kind 不合法"，于是继续按错误前提往下走。
+/// `unknown` 本身仍是合法输入（确有 kind 未知的资产），只拒绝"既不是 canonical、也不是字面
+/// `unknown`"的原值。
+fn bridge_asset_list_kind_filter(raw: &str) -> Result<GameCreationAppAssetKind, String> {
+    let kind = GameCreationAppAssetKind::parse_with_context(raw, "asset.list.kind");
+    if kind == GameCreationAppAssetKind::Unknown
+        && raw.trim() != GameCreationAppAssetKind::Unknown.as_str()
+    {
+        return Err(format!(
+            "kind 不是已知的 manifest 资源 kind：{raw}；请改用 canonical kind（如 image、scene、character、icon、icon-spritesheet、character-animation、audio、video、document）"
+        ));
+    }
+    Ok(kind)
+}
+
 fn bridge_project_file_class(path: &str) -> (&'static str, Option<&'static str>) {
     let extension = Path::new(path)
         .extension()
@@ -2745,6 +2764,28 @@ mod tests {
             .contains("x-genarrative-client:"));
     }
 
+    /// `asset.list` 的 `kind` 过滤必须报错，而不是静默返回空列表：旧值会收口成 `unknown` 再参与
+    /// 等值过滤，匹配不到任何资产，让模型误以为项目里没有这类资产。校验必须发生在项目访问之前。
+    #[test]
+    fn bridge_asset_list_rejects_non_canonical_kind_filter() {
+        let root = tempfile::tempdir().expect("bridge root");
+        let rejected =
+            bridge_list_registered_assets(root.path(), &json!({ "kind": "art-spritesheet-slice" }));
+        assert_eq!(rejected["isError"], true);
+        assert!(
+            rejected.to_string().contains("art-spritesheet-slice"),
+            "错误里必须带上原值，调用方才能自纠：{rejected}"
+        );
+        // 字面 `unknown` 仍是合法过滤值：它应当越过 kind 校验，失败点换成项目侧（此目录未初始化）。
+        let allowed = bridge_list_registered_assets(root.path(), &json!({ "kind": "unknown" }));
+        assert!(
+            !allowed
+                .to_string()
+                .contains("不是已知的 manifest 资源 kind"),
+            "未知 kind 的字面量本身是合法输入：{allowed}"
+        );
+    }
+
     #[test]
     fn bridge_argument_bounds_are_deterministic() {
         assert_eq!(
diff --git a/apps/ai-game-creator-shell/src-tauri/src/agent/direct_tools_mcp.rs b/apps/ai-game-creator-shell/src-tauri/src/agent/direct_tools_mcp.rs
index f242153cd..af2421e91 100644
--- a/apps/ai-game-creator-shell/src-tauri/src/agent/direct_tools_mcp.rs
+++ b/apps/ai-game-creator-shell/src-tauri/src/agent/direct_tools_mcp.rs
@@ -307,7 +307,7 @@ fn direct_tools_mcp_specs_for(controlled_web_search: bool, _cocos_editor_availab
                             "type": "string",
                             "minLength": 1,
                             "maxLength": 80,
-                            "description": "可选的 manifest 资源 kind 精确过滤，例如 video、character-animation、sound-effect、background-music 或 icon-spritesheet"
+                            "description": "可选的 manifest 资源 kind 精确过滤，必须是 canonical kind（例如 video、character-animation、sound-effect、background-music、icon-spritesheet）；传非 canonical 值会被拒绝并报错，不会静默返回空列表"
                         },
                         "assetId": {
                             "type": "string",