diff --git a/src-tauri/src/commands/ai/tool_registry.rs b/src-tauri/src/commands/ai/tool_registry.rs
index 21e182e..c0533ca 100644
--- a/src-tauri/src/commands/ai/tool_registry.rs
+++ b/src-tauri/src/commands/ai/tool_registry.rs
@@ -140,20 +140,22 @@ pub fn build_ai_tool_registry(db: &Arc<Database>) -> AiToolRegistry {
 
     // ── 只读 (Low) ──
     registry.register(
-        "list_projects", "列出所有项目，返回项目列表（ID、名称、状态、描述）",
+        "list_projects", "列出所有项目，返回项目列表（ID、名称、状态、描述）。最多返回 50 条",
         df_ai::ai_tools::object_schema(vec![]), RiskLevel::Low,
         { let db = db.clone(); Box::new(move |_args: serde_json::Value| {
             let db = db.clone();
             Box::pin(async move {
                 let repo = df_storage::crud::ProjectRepo::new(&db);
                 let mut items = repo.list_active().await?; // list_active 排除回收站(deleted_at)，防 LLM 看到已软删项目
+                let total = items.len();
+                let truncated = total > 50;
                 items.truncate(50); // 防 LLM context 膨胀
-                Ok(serde_json::to_value(items)?)
+                Ok(serde_json::json!({ "items": items, "truncated": truncated }))
             })
         })},
     );
     registry.register(
-        "list_tasks", "列出任务，可按 project_id 筛选",
+        "list_tasks", "列出任务，可按 project_id 筛选。最多返回 50 条",
         df_ai::ai_tools::object_schema(vec![("project_id", "string", false)]), RiskLevel::Low,
         { let db = db.clone(); Box::new(move |args: serde_json::Value| {
             let db = db.clone();
@@ -164,21 +166,25 @@ pub fn build_ai_tool_registry(db: &Arc<Database>) -> AiToolRegistry {
                 } else {
                     repo.list_all().await?
                 };
+                let total = tasks.len();
+                let truncated = total > 50;
                 tasks.truncate(50); // 防 LLM context 膨胀
-                Ok(serde_json::to_value(tasks)?)
+                Ok(serde_json::json!({ "items": tasks, "truncated": truncated }))
             })
         })},
     );
     registry.register(
-        "list_ideas", "列出所有灵感",
+        "list_ideas", "列出所有灵感。最多返回 50 条",
         df_ai::ai_tools::object_schema(vec![]), RiskLevel::Low,
         { let db = db.clone(); Box::new(move |_args: serde_json::Value| {
             let db = db.clone();
             Box::pin(async move {
                 let repo = df_storage::crud::IdeaRepo::new(&db);
                 let mut items = repo.list_all().await?;
+                let total = items.len();
+                let truncated = total > 50;
                 items.truncate(50); // 防 LLM context 膨胀
-                Ok(serde_json::to_value(items)?)
+                Ok(serde_json::json!({ "items": items, "truncated": truncated }))
             })
         })},
     );
diff --git a/src/components/AiChat.vue b/src/components/AiChat.vue
index db58c58..618932c 100644
--- a/src/components/AiChat.vue
+++ b/src/components/AiChat.vue
@@ -709,9 +709,12 @@ function onMessagesScroll() {
   refreshBackToBottom()
 }
 
-function scrollToBottom() {
+function scrollToBottom(smooth = false) {
   if (messagesContainer.value) {
-    messagesContainer.value.scrollTop = messagesContainer.value.scrollHeight
+    messagesContainer.value.scrollTo({
+      top: messagesContainer.value.scrollHeight,
+      behavior: smooth ? 'smooth' : 'instant',
+    })
     showBackToBottom.value = false
   }
 }