diff --git a/src/agent/agent_loop.rs b/src/agent/agent_loop.rs
index 4e9c856..42a0d2c 100644
--- a/src/agent/agent_loop.rs
+++ b/src/agent/agent_loop.rs
@@ -341,7 +341,7 @@ impl AgentLoop {
         // Build and inject system prompt if not present
         let has_system = messages.first().map_or(false, |m| m.role == "system");
         if !has_system {
-            let system_prompt = build_system_prompt(&self.workspace_dir, &self.model_name, &self.tools);
+            let system_prompt = build_system_prompt(&self.workspace_dir, &self.model_name, &self.tools, None);
             #[cfg(debug_assertions)]
             tracing::debug!("System prompt injected:\n{}", system_prompt);
             messages.insert(0, ChatMessage::system(system_prompt));
diff --git a/src/agent/system_prompt.rs b/src/agent/system_prompt.rs
index 4a2b976..de63f93 100644
--- a/src/agent/system_prompt.rs
+++ b/src/agent/system_prompt.rs
@@ -18,6 +18,7 @@ pub struct PromptContext<'a> {
     pub workspace_dir: &'a Path,
     pub model_name: &'a str,
     pub tools: &'a ToolRegistry,
+    pub session_id: Option<&'a str>,
 }
 
 /// Trait for system prompt sections.
@@ -222,37 +223,43 @@ impl PromptSection for CrossChannelSection {
         "cross_channel"
     }
 
-    fn build(&self, _ctx: &PromptContext<'_>) -> String {
-        r#"## 关于跨渠道消息和系统通知
+    fn build(&self, ctx: &PromptContext<'_>) -> String {
+        let session_line = if let Some(id) = ctx.session_id {
+            format!("当前会话的 ID 是 `{}`。\n", id)
+        } else {
+            String::new()
+        };
 
-当前对话中可能出现带有 `source` 标记的消息，这些消息不是用户直接输入：
+        format!(
+            r#"## 关于会话和跨渠道消息
 
-### 系统通知（source.kind = "system_notification"）
-来自机器人内部系统（如定时任务、后台任务）的通知。
-- `system_name`: 发出通知的系统名称
-- `task_id`: 关联的任务 ID
+### 会话 ID 格式
+每个会话都有唯一的 session ID，由三部分组成：<channel>:<chat_id>:<dialog_id>
+- channel: 消息渠道（如 "cli_chat"、"feishu"）
+- chat_id: 聊天/群组标识
+- dialog_id: 对话标识，同一 chat 下可以有多个 dialog
 
-### 跨渠道消息（source.kind = "cross_channel"）
-来自其他渠道的消息被写入当前对话。
-- `from_channel`: 来源渠道（如 "feishu"）
-- `from_user_id`: 来源用户 ID
+{}### 跨会话消息
+对话历史中可能出现带有 `[message from X to Y]` 前缀的 assistant 消息，
+表示此消息由 send_message 工具从别处发送过来。
+- X: 来源标识，可能是会话 ID、工具名或其他标识字符串；未指定时为 "unknown"
+- Y: 目标会话的完整 session ID (<channel>:<chat_id>:<dialog_id>)
+
+收到此类消息时一般不需要主动处理，只需知晓。如果用户问及相关信息，
+可以尝试从来源处获取更多详情。
 
 ### send_message 工具
+向指定会话发送消息。参数：
+- target_chat_id: 格式 <channel>:<chat_id> 或 <channel>:<chat_id>:<dialog_id>
+- content: 消息内容
 
-使用 `send_message` 向其他渠道发送消息。参数：
-- `target_chat_id`: 目标会话ID，支持两种格式：
-  1. `<channel>:<chat_id>` — 发送到该聊天下最新活跃的会话，若没有活跃会话则自动创建
-  2. `<channel>:<chat_id>:<dialog_id>` — 发送到指定会话，若会话已过期则自动激活
-- `content`: 要发送的消息内容
-- `origin`（可选）: 消息来源标识，不填则自动使用当前会话的完整 session_id
-
-跨渠道消息到达目标会话时，内容前会带有 `[message from X to Y]` 标记，
-表示该消息的来源和目标。目标会话的 LLM 应将此理解为来自其他渠道/会话的消息。
-
-### 处理建议
-- 系统通知：可以提及但不建议以此为由改变对话主题
-- 跨渠道消息：当用户提及相关事务时可关联这些消息"#
-            .to_string()
+### chat_manager 工具
+管理会话和查看消息。参数：
+- action = "list_sessions" — 列出最近活跃的会话
+- action = "list_channels" — 列出所有可用渠道
+- action = "list_messages" — 查看指定 session 的最近消息，需提供 session_id 和 count"#,
+            session_line
+        )
     }
 }
 
@@ -314,11 +321,12 @@ fn load_file_from_dir(dir: &Path, filename: &str, max_chars: usize) -> Option<St
 }
 
 /// Build a complete system prompt with default configuration.
-pub fn build_system_prompt(workspace_dir: &Path, model_name: &str, tools: &ToolRegistry) -> String {
+pub fn build_system_prompt(workspace_dir: &Path, model_name: &str, tools: &ToolRegistry, session_id: Option<&str>) -> String {
     let ctx = PromptContext {
         workspace_dir,
         model_name,
         tools,
+        session_id,
     };
     SystemPromptBuilder::with_defaults().build(&ctx)
 }
@@ -337,6 +345,7 @@ mod tests {
             workspace_dir: &temp_dir,
             model_name: "test-model",
             tools: &tools,
+            session_id: None,
         };
 
         let prompt = SystemPromptBuilder::with_defaults().build(&ctx);
@@ -366,7 +375,7 @@ mod tests {
         let temp_dir = std::env::temp_dir();
         let tools = ToolRegistry::new();
 
-        let prompt = build_system_prompt(&temp_dir, "test-model", &tools);
+        let prompt = build_system_prompt(&temp_dir, "test-model", &tools, None);
 
         assert!(!prompt.is_empty());
         assert!(prompt.contains("test-model"));
diff --git a/src/gateway/mod.rs b/src/gateway/mod.rs
index 78f3f55..e4ea877 100644
--- a/src/gateway/mod.rs
+++ b/src/gateway/mod.rs
@@ -78,6 +78,11 @@ impl GatewayState {
         let valid_channels = available_channels.clone();
         session_manager.register_outbound_tool(available_channels);
 
+        // Register chat_manager tool
+        session_manager.tools().register(
+            crate::tools::ChatManagerTool::new(storage.clone(), valid_channels.clone()),
+        );
+
         // Initialize scheduler if enabled in config
         let scheduler_config = config.gateway.scheduler.clone().unwrap_or_default();
         if scheduler_config.enabled {
@@ -204,6 +209,7 @@ impl GatewayState {
             let sched = Arc::new(Scheduler::new(
                 self.storage.clone(),
                 self.session_manager.clone(),
+                self.channel_manager.bus(),
                 scheduler_config,
             ));
             tokio::spawn(async move {
diff --git a/src/scheduler/mod.rs b/src/scheduler/mod.rs
index f70c4d1..acf0275 100644
--- a/src/scheduler/mod.rs
+++ b/src/scheduler/mod.rs
@@ -4,6 +4,7 @@ use std::sync::Arc;
 use std::time::Instant;
 use tokio::time;
 
+use crate::bus::MessageBus;
 use crate::config::SchedulerConfig;
 use crate::session::session::HandleResult;
 use crate::session::SessionManager;
@@ -52,6 +53,7 @@ fn now_ms() -> i64 {
 pub struct Scheduler {
     storage: Arc<Storage>,
     session_manager: Arc<SessionManager>,
+    bus: Arc<MessageBus>,
     config: SchedulerConfig,
 }
 
@@ -59,11 +61,13 @@ impl Scheduler {
     pub fn new(
         storage: Arc<Storage>,
         session_manager: Arc<SessionManager>,
+        bus: Arc<MessageBus>,
         config: SchedulerConfig,
     ) -> Self {
         Self {
             storage,
             session_manager,
+            bus,
             config,
         }
     }
@@ -132,6 +136,16 @@ impl Scheduler {
 
                 match result {
                     Ok(HandleResult::AgentResponse(output)) => {
+                        let outbound = crate::bus::OutboundMessage {
+                            channel: job.channel.clone(),
+                            chat_id: job.chat_id.clone(),
+                            content: output.clone(),
+                            reply_to: None,
+                            media: vec![],
+                            metadata: std::collections::HashMap::new(),
+                        };
+                        let _ = self.bus.publish_outbound(outbound).await;
+
                         let output_truncated = if output.len() > 8000 {
                             format!("{}...[truncated]", &output[..8000])
                         } else {
@@ -164,6 +178,16 @@ impl Scheduler {
                         );
                     }
                     Ok(HandleResult::CommandOutput(output)) => {
+                        let outbound = crate::bus::OutboundMessage {
+                            channel: job.channel.clone(),
+                            chat_id: job.chat_id.clone(),
+                            content: output.clone(),
+                            reply_to: None,
+                            media: vec![],
+                            metadata: std::collections::HashMap::new(),
+                        };
+                        let _ = self.bus.publish_outbound(outbound).await;
+
                         let run = JobRun {
                             id: 0,
                             job_id: job.id.clone(),
diff --git a/src/session/session.rs b/src/session/session.rs
index ebd7330..fa88f32 100644
--- a/src/session/session.rs
+++ b/src/session/session.rs
@@ -378,6 +378,7 @@ impl Session {
             &self.provider_config.workspace_dir,
             &self.provider_config.model_id,
             &self.tools,
+            Some(&self.id.to_string()),
         );
 
         if skills_prompt.trim().is_empty() {
@@ -1324,7 +1325,20 @@ impl SessionManager {
 
             let skills_prompt = self.skills_loader.build_skills_prompt();
             let system_prompt = session_guard.build_system_prompt(&skills_prompt);
-            history.insert(0, ChatMessage::system(system_prompt));
+            let cron_context = format!(
+                "\n\n## 定时任务执行\n\n\
+                 你正在执行定时任务「{}」({})。\n\
+                 目标渠道: {}:{}\n\n\
+                 定时任务执行规则：\n\
+                 - 这不是聊天对话，没有人会回复你，不要等待用户输入\n\
+                 - 你的职责是根据任务指令直接生成要发送的消息内容\n\
+                 - 只输出最终消息，不要输出中间思考过程或分析\n\
+                 - 系统会自动将你的回复推送到目标渠道，不要使用 send_message 工具\n\
+                 - 你的最终回复就是推送给用户的消息原文",
+                job_name, job_id, channel, chat_id
+            );
+            let full_system_prompt = format!("{}{}", system_prompt, cron_context);
+            history.insert(0, ChatMessage::system(full_system_prompt));
 
             let history = session_guard.compressor
                 .compress_if_needed(history)
@@ -1344,7 +1358,28 @@ impl SessionManager {
                 }
             }
 
-            result.final_response.content
+            let raw_response = result.final_response.content;
+
+            let target_id = unified_id.to_string();
+            let prefix = format!(
+                "[message from cron:{}({}) to {}]\n",
+                job_name, job_id, target_id
+            );
+            let prefixed_response = format!("{}{}", prefix, raw_response);
+
+            let source = MessageSource {
+                kind: SourceKind::CrossChannel,
+                from_channel: Some("cron".to_string()),
+                from_session: Some(format!("{}:{}", job_name, job_id)),
+                from_user_id: None,
+                system_name: Some(job_name.to_string()),
+                task_id: Some(job_id.to_string()),
+            };
+            let msg = ChatMessage::assistant_with_source(prefixed_response.clone(), source);
+            session_guard.add_message(msg, true).await
+                .map_err(|e| AgentError::Other(format!("persist error: {}", e)))?;
+
+            prefixed_response
         };
 
         #[cfg(debug_assertions)]
diff --git a/src/storage/mod.rs b/src/storage/mod.rs
index df77744..e581bf8 100644
--- a/src/storage/mod.rs
+++ b/src/storage/mod.rs
@@ -465,6 +465,79 @@ impl Storage {
             .collect())
     }
 
+    pub async fn list_all_active_sessions(
+        &self,
+        limit: i64,
+    ) -> Result<Vec<crate::storage::session::SessionMeta>, StorageError> {
+        let rows = sqlx::query(
+            r#"
+            SELECT id, channel, chat_id, dialog_id, title, created_at, last_active_at, message_count, routing_info, deleted_at
+            FROM sessions
+            WHERE deleted_at IS NULL
+            ORDER BY last_active_at DESC
+            LIMIT ?
+            "#,
+        )
+        .bind(limit)
+        .fetch_all(self.pool())
+        .await?;
+
+        Ok(rows
+            .into_iter()
+            .map(|row| crate::storage::session::SessionMeta {
+                id: row.get("id"),
+                channel: row.get("channel"),
+                chat_id: row.get("chat_id"),
+                dialog_id: row.get("dialog_id"),
+                title: row.get("title"),
+                created_at: row.get("created_at"),
+                last_active_at: row.get("last_active_at"),
+                message_count: row.get("message_count"),
+                routing_info: row.get("routing_info"),
+                deleted_at: row.get("deleted_at"),
+            })
+            .collect())
+    }
+
+    pub async fn list_recent_messages(
+        &self,
+        session_id: &str,
+        count: i64,
+    ) -> Result<Vec<crate::storage::message::MessageMeta>, StorageError> {
+        let rows = sqlx::query(
+            r#"
+            SELECT id, session_id, seq, role, content, media_refs, tool_call_id, tool_name, tool_calls, source, created_at
+            FROM messages
+            WHERE session_id = ?
+            ORDER BY seq DESC
+            LIMIT ?
+            "#,
+        )
+        .bind(session_id)
+        .bind(count)
+        .fetch_all(self.pool())
+        .await?;
+
+        let mut messages: Vec<_> = rows
+            .into_iter()
+            .map(|row| crate::storage::message::MessageMeta {
+                id: row.get("id"),
+                session_id: row.get("session_id"),
+                seq: row.get("seq"),
+                role: row.get("role"),
+                content: row.get("content"),
+                media_refs: row.get("media_refs"),
+                tool_call_id: row.get("tool_call_id"),
+                tool_name: row.get("tool_name"),
+                tool_calls: row.get("tool_calls"),
+                source: row.get("source"),
+                created_at: row.get("created_at"),
+            })
+            .collect();
+        messages.reverse();
+        Ok(messages)
+    }
+
     pub async fn clear_messages(&self, session_id: &str) -> Result<(), StorageError> {
         sqlx::query(r#"DELETE FROM messages WHERE session_id = ?"#)
             .bind(session_id)
diff --git a/src/tools/chat_manager.rs b/src/tools/chat_manager.rs
new file mode 100644
index 0000000..4a5bf28
--- /dev/null
+++ b/src/tools/chat_manager.rs
@@ -0,0 +1,343 @@
+use std::sync::Arc;
+
+use async_trait::async_trait;
+use serde_json::json;
+
+use crate::storage::Storage;
+use crate::tools::traits::{Tool, ToolResult};
+
+pub struct ChatManagerTool {
+    storage: Arc<Storage>,
+    available_channels: Vec<String>,
+}
+
+impl ChatManagerTool {
+    pub fn new(storage: Arc<Storage>, available_channels: Vec<String>) -> Self {
+        Self {
+            storage,
+            available_channels,
+        }
+    }
+}
+
+#[async_trait]
+impl Tool for ChatManagerTool {
+    fn name(&self) -> &str {
+        "chat_manager"
+    }
+
+    fn description(&self) -> &str {
+        "聊天管理工具。可以列出当前活跃的 session、可用的 channel、以及查看指定 session 的最近消息内容。\
+action 可选值: list_sessions (列出最近活跃会话), list_channels (列出可用渠道), list_messages (查看最近消息)"
+    }
+
+    fn parameters_schema(&self) -> serde_json::Value {
+        json!({
+            "type": "object",
+            "properties": {
+                "action": {
+                    "type": "string",
+                    "enum": ["list_sessions", "list_channels", "list_messages"],
+                    "description": "操作类型: list_sessions 列出最近活跃会话, list_channels 列出可用渠道, list_messages 查看指定会话的最近消息"
+                },
+                "session_id": {
+                    "type": "string",
+                    "description": "会话 ID，格式 channel:chat_id:dialog_id，仅在 action 为 list_messages 时必填"
+                },
+                "count": {
+                    "type": "integer",
+                    "description": "获取最近消息的数量，仅在 action 为 list_messages 时有效，默认 20"
+                }
+            },
+            "required": ["action"]
+        })
+    }
+
+    fn read_only(&self) -> bool {
+        true
+    }
+
+    fn concurrency_safe(&self) -> bool {
+        true
+    }
+
+    async fn execute(&self, args: serde_json::Value) -> anyhow::Result<ToolResult> {
+        let action = args["action"]
+            .as_str()
+            .ok_or_else(|| anyhow::anyhow!("missing required parameter: action"))?;
+
+        match action {
+            "list_channels" => self.list_channels().await,
+            "list_sessions" => self.list_sessions().await,
+            "list_messages" => self.list_messages(&args).await,
+            _ => Ok(ToolResult {
+                success: false,
+                output: String::new(),
+                error: Some(format!(
+                    "Unknown action: {}. Supported: list_sessions, list_channels, list_messages",
+                    action
+                )),
+            }),
+        }
+    }
+}
+
+impl ChatManagerTool {
+    async fn list_channels(&self) -> anyhow::Result<ToolResult> {
+        let channels = self.available_channels.join(", ");
+        Ok(ToolResult {
+            success: true,
+            output: format!("可用渠道 ({}): {}", self.available_channels.len(), channels),
+            error: None,
+        })
+    }
+
+    async fn list_sessions(&self) -> anyhow::Result<ToolResult> {
+        let sessions = self
+            .storage
+            .list_all_active_sessions(20)
+            .await
+            .map_err(|e| anyhow::anyhow!("Failed to list sessions: {}", e))?;
+
+        if sessions.is_empty() {
+            return Ok(ToolResult {
+                success: true,
+                output: "当前没有活跃的会话".to_string(),
+                error: None,
+            });
+        }
+
+        let now_ms = chrono::Utc::now().timestamp_millis();
+        let mut output = format!("活跃会话 (共 {} 个):\n", sessions.len());
+
+        for s in &sessions {
+            let ago = format_duration_ago(now_ms - s.last_active_at);
+            output.push_str(&format!(
+                "- {}\n  title={} | channel={} chat_id={} | {}条消息 | 最后活动: {}前\n",
+                s.id, s.title, s.channel, s.chat_id, s.message_count, ago
+            ));
+        }
+
+        Ok(ToolResult {
+            success: true,
+            output,
+            error: None,
+        })
+    }
+
+    async fn list_messages(&self, args: &serde_json::Value) -> anyhow::Result<ToolResult> {
+        let session_id = args["session_id"]
+            .as_str()
+            .ok_or_else(|| anyhow::anyhow!("missing required parameter: session_id"))?;
+
+        let count = args["count"].as_i64().unwrap_or(20).clamp(1, 100);
+
+        let session = self
+            .storage
+            .get_session(session_id)
+            .await
+            .map_err(|e| anyhow::anyhow!("Session not found: {}", e))?;
+
+        let messages = self
+            .storage
+            .list_recent_messages(session_id, count)
+            .await
+            .map_err(|e| anyhow::anyhow!("Failed to load messages: {}", e))?;
+
+        let mut output = format!(
+            "会话: {} ({})\n--- 最近 {} 条消息 (共 {} 条) ---\n",
+            session_id, session.title, messages.len(), session.message_count
+        );
+
+        if messages.is_empty() {
+            output.push_str("(暂无消息)\n");
+        } else {
+            for m in &messages {
+                let time = format_timestamp(m.created_at);
+                let role_tag = match m.role.as_str() {
+                    "user" => "user     ",
+                    "assistant" => "assistant",
+                    "tool" => "tool     ",
+                    "system" => "system   ",
+                    other => other,
+                };
+                let preview = truncate_content(&m.content, 200);
+                output.push_str(&format!(
+                    "[{}] {} | {} | {}\n",
+                    m.seq, time, role_tag, preview
+                ));
+            }
+        }
+
+        Ok(ToolResult {
+            success: true,
+            output,
+            error: None,
+        })
+    }
+}
+
+fn format_duration_ago(millis: i64) -> String {
+    let secs = millis / 1000;
+    if secs < 60 {
+        format!("{}秒", secs)
+    } else if secs < 3600 {
+        format!("{}分钟", secs / 60)
+    } else if secs < 86400 {
+        format!("{}小时", secs / 3600)
+    } else {
+        format!("{}天", secs / 86400)
+    }
+}
+
+fn format_timestamp(ms: i64) -> String {
+    if let Some(dt) = chrono::DateTime::from_timestamp_millis(ms) {
+        dt.format("%m-%d %H:%M").to_string()
+    } else {
+        ms.to_string()
+    }
+}
+
+fn truncate_content(content: &str, max_len: usize) -> String {
+    let content = content.replace('\n', " ");
+    if content.chars().count() > max_len {
+        format!("{}...", content.chars().take(max_len).collect::<String>())
+    } else {
+        content
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use tempfile::TempDir;
+
+    async fn create_test_storage() -> (Arc<Storage>, TempDir) {
+        let dir = tempfile::tempdir().unwrap();
+        let db_path = dir.path().join("test.db");
+        let storage = Storage::new(&db_path).await.unwrap();
+        (Arc::new(storage), dir)
+    }
+
+    #[tokio::test]
+    async fn test_list_channels() {
+        let (storage, _dir) = create_test_storage().await;
+        let tool = ChatManagerTool::new(storage, vec!["cli_chat".into(), "feishu".into()]);
+
+        let result = tool
+            .execute(json!({ "action": "list_channels" }))
+            .await
+            .unwrap();
+        assert!(result.success);
+        assert!(result.output.contains("cli_chat"));
+        assert!(result.output.contains("feishu"));
+    }
+
+    #[tokio::test]
+    async fn test_list_sessions_empty() {
+        let (storage, _dir) = create_test_storage().await;
+        let tool = ChatManagerTool::new(storage, vec![]);
+
+        let result = tool
+            .execute(json!({ "action": "list_sessions" }))
+            .await
+            .unwrap();
+        assert!(result.success);
+        assert!(result.output.contains("没有"));
+    }
+
+    #[tokio::test]
+    async fn test_list_sessions_with_data() {
+        let (storage, _dir) = create_test_storage().await;
+
+        let now = chrono::Utc::now().timestamp_millis();
+        for i in 0..3 {
+            let meta = crate::storage::session::SessionMeta {
+                id: format!("cli_chat:sid{}:dialog{}", i, i),
+                channel: "cli_chat".to_string(),
+                chat_id: format!("sid{}", i),
+                dialog_id: format!("dialog{}", i),
+                title: format!("会话{}", i),
+                created_at: now - i * 3600_000,
+                last_active_at: now - i * 3600_000,
+                message_count: i * 5,
+                routing_info: None,
+                deleted_at: None,
+            };
+            storage.upsert_session(&meta).await.unwrap();
+        }
+
+        let tool = ChatManagerTool::new(storage, vec![]);
+
+        let result = tool
+            .execute(json!({ "action": "list_sessions" }))
+            .await
+            .unwrap();
+        assert!(result.success);
+        assert!(result.output.contains("会话0"));
+        assert!(result.output.contains("会话1"));
+        assert!(result.output.contains("会话2"));
+    }
+
+    #[tokio::test]
+    async fn test_list_messages() {
+        let (storage, _dir) = create_test_storage().await;
+
+        let now = chrono::Utc::now().timestamp_millis();
+        let session_id = "cli_chat:sid0:dialog0";
+        let meta = crate::storage::session::SessionMeta {
+            id: session_id.to_string(),
+            channel: "cli_chat".to_string(),
+            chat_id: "sid0".to_string(),
+            dialog_id: "dialog0".to_string(),
+            title: "测试会话".to_string(),
+            created_at: now,
+            last_active_at: now,
+            message_count: 3,
+            routing_info: None,
+            deleted_at: None,
+        };
+        storage.upsert_session(&meta).await.unwrap();
+
+        for i in 0..3 {
+            let msg = crate::storage::message::MessageMeta {
+                id: format!("msg{}", i),
+                session_id: session_id.to_string(),
+                seq: i as i64 + 1,
+                role: if i == 0 { "user".to_string() } else { "assistant".to_string() },
+                content: format!("消息内容 {}", i),
+                media_refs: None,
+                tool_call_id: None,
+                tool_name: None,
+                tool_calls: None,
+                source: None,
+                created_at: now + i * 1000,
+            };
+            storage.append_message(session_id, &msg).await.unwrap();
+        }
+
+        let tool = ChatManagerTool::new(storage, vec![]);
+
+        let result = tool
+            .execute(json!({ "action": "list_messages", "session_id": session_id }))
+            .await
+            .unwrap();
+        assert!(result.success);
+        assert!(result.output.contains("消息内容 0"));
+        assert!(result.output.contains("消息内容 2"));
+        assert!(result.output.contains("测试会话"));
+    }
+
+    #[tokio::test]
+    async fn test_unknown_action() {
+        let (storage, _dir) = create_test_storage().await;
+        let tool = ChatManagerTool::new(storage, vec![]);
+
+        let result = tool
+            .execute(json!({ "action": "unknown" }))
+            .await
+            .unwrap();
+        assert!(!result.success);
+        assert!(result.error.unwrap().contains("Unknown action"));
+    }
+}
diff --git a/src/tools/cron.rs b/src/tools/cron.rs
index e180870..f8d83de 100644
--- a/src/tools/cron.rs
+++ b/src/tools/cron.rs
@@ -38,6 +38,9 @@ impl Tool for CronAddTool {
     fn description(&self) -> &str {
         "Create a new scheduled task (cron job). The task will execute an AI prompt on a schedule \
          and deliver the result to the specified channel/chat. \
+         Important: the execution environment is a fresh session with no access to your current \
+         conversation history. The prompt parameter MUST include all necessary context: \
+         what to do, the target audience, required output format, and any background information. \
          Schedule formats: \
          - 'every': {\"type\":\"every\",\"every_ms\":3600000} for every hour, \
          - 'at': {\"type\":\"at\",\"at\":<unix_timestamp_ms>} for one-shot, \
diff --git a/src/tools/mod.rs b/src/tools/mod.rs
index a007f5b..b08adf9 100644
--- a/src/tools/mod.rs
+++ b/src/tools/mod.rs
@@ -1,5 +1,6 @@
 pub mod bash;
 pub mod calculator;
+pub mod chat_manager;
 pub mod cron;
 pub mod file_edit;
 pub mod file_read;
@@ -14,6 +15,7 @@ pub mod web_fetch;
 
 pub use bash::BashTool;
 pub use calculator::CalculatorTool;
+pub use chat_manager::ChatManagerTool;
 pub use file_edit::FileEditTool;
 pub use file_read::FileReadTool;
 pub use file_write::FileWriteTool;