diff --git a/crates/tui/src/app.rs b/crates/tui/src/app.rs
index 205410de..a6d608cb 100644
--- a/crates/tui/src/app.rs
+++ b/crates/tui/src/app.rs
@@ -3539,7 +3539,9 @@ mod completion_flow_tests {
                 arguments: args.into(),
             });
         }
-        assert!(app.task_store.tasks().is_empty());
+        let tasks = app.task_store.tasks();
+        assert_eq!(tasks.len(), 1);
+        assert_eq!(tasks[0].status, crate::task::TaskStatus::Completed);
     }
 
     #[test]
diff --git a/crates/tui/src/task.rs b/crates/tui/src/task.rs
index 537e7853..81e7f931 100644
--- a/crates/tui/src/task.rs
+++ b/crates/tui/src/task.rs
@@ -28,8 +28,8 @@ pub enum TaskStatus {
 }
 
 impl TaskStatus {
-    fn is_active(self) -> bool {
-        matches!(self, Self::Pending | Self::Inprogress)
+    fn is_retained(self) -> bool {
+        !matches!(self, Self::Deleted)
     }
 }
 
@@ -125,7 +125,7 @@ impl TaskStore {
                     if let Some(d) = p.description {
                         t.description = d;
                     }
-                    if !t.status.is_active() {
+                    if !t.status.is_retained() {
                         self.tasks.remove(task_position);
                     }
                 }
@@ -145,7 +145,7 @@ impl TaskStore {
     fn replace_with(&mut self, tasks: Vec<TaskEntry>) {
         let tasks: Vec<_> = tasks
             .into_iter()
-            .filter(|task| task.status.is_active())
+            .filter(|task| task.status.is_retained())
             .collect();
         self.next_taskid = tasks
             .iter()
@@ -194,7 +194,7 @@ fn parse_snapshot_text(text: &str) -> Option<Vec<TaskEntry>> {
         snapshot
             .tasks
             .into_iter()
-            .filter(|task| task.status.is_active())
+            .filter(|task| task.status.is_retained())
             .collect(),
     )
 }
@@ -241,7 +241,7 @@ mod tests {
     }
 
     #[test]
-    fn counts_tracks_only_active_tasks_after_completion() {
+    fn counts_retains_completed_tasks_until_deleted() {
         let mut s = TaskStore::new();
         s.apply_tool_call("TaskCreate", r#"{"subject":"a","description":""}"#);
         s.apply_tool_call("TaskCreate", r#"{"subject":"b","description":""}"#);
@@ -251,10 +251,13 @@ mod tests {
         let c = s.counts();
         assert_eq!(c.pending, 1);
         assert_eq!(c.inprogress, 1);
-        assert_eq!(c.completed, 0);
+        assert_eq!(c.completed, 1);
         assert_eq!(c.deleted, 0);
-        assert_eq!(c.total(), 2);
+        assert_eq!(c.total(), 3);
         assert_eq!(c.active(), 2);
+
+        s.apply_tool_call("TaskUpdate", r#"{"taskid":2,"status":"deleted"}"#);
+        assert!(s.tasks().iter().all(|task| task.taskid != 2));
     }
 
     /// Snapshot text matches the wrapping `Worker::try_pre_run_compact` and the
@@ -263,7 +266,7 @@ mod tests {
     fn wrap_snapshot(json_body: &str, overview: &str) -> String {
         format!(
             "[Session TaskStore snapshot]\n\n{overview}\n\n```json\n{json_body}\n```\n\n\
-             This is the active session task list preserved across compaction. \
+             This is the retained session task list preserved across compaction. \
              The following TaskList tool result presents the same state through the tool lane."
         )
     }
@@ -288,19 +291,21 @@ mod tests {
 }"#;
         let text = wrap_snapshot(
             body,
-            "TaskStore: 1 active task(s) (pending: 1, inprogress: 0)",
+            "TaskStore: 2 task(s) (pending: 1, inprogress: 0, completed: 1)",
         );
         let mut s = TaskStore::new();
         s.apply_tool_call("TaskCreate", r#"{"subject":"stale","description":""}"#);
         s.apply_system_message_text(&text);
         let tasks = s.tasks();
-        assert_eq!(tasks.len(), 1);
-        assert_eq!(tasks[0].taskid, 7);
-        assert_eq!(tasks[0].status, TaskStatus::Pending);
-        // Subsequent TaskCreate must continue beyond the highest active taskid
+        assert_eq!(tasks.len(), 2);
+        assert_eq!(tasks[0].taskid, 5);
+        assert_eq!(tasks[0].status, TaskStatus::Completed);
+        assert_eq!(tasks[1].taskid, 7);
+        assert_eq!(tasks[1].status, TaskStatus::Pending);
+        // Subsequent TaskCreate must continue beyond the highest retained taskid
         // observed in the snapshot.
         s.apply_tool_call("TaskCreate", r#"{"subject":"new","description":""}"#);
-        assert_eq!(s.tasks()[1].taskid, 8);
+        assert_eq!(s.tasks()[2].taskid, 8);
     }
 
     #[test]
@@ -324,7 +329,7 @@ mod tests {
     }
   ]
 }"#;
-        let text = wrap_snapshot(body, "TaskStore: 1 active task(s)");
+        let text = wrap_snapshot(body, "TaskStore: 1 task(s)");
         let mut s = TaskStore::new();
         s.apply_system_message_text(&text);
         let t = &s.tasks()[0];
@@ -349,13 +354,13 @@ mod snapshot_format_contract {
     fn wrap_pod_style(snapshot_text: &str) -> String {
         format!(
             "[Session TaskStore snapshot]\n\n{snapshot_text}\n\n\
-             This is the active session task list preserved across compaction. \
+             This is the retained session task list preserved across compaction. \
              The following TaskList tool result presents the same state through the tool lane."
         )
     }
 
     fn snapshot_fixture() -> &'static str {
-        r#"TaskStore: 1 active task(s) (pending: 0, inprogress: 1)
+        r#"TaskStore: 1 task(s) (pending: 0, inprogress: 1, completed: 0)
 
 ```json
 {
@@ -372,7 +377,7 @@ mod snapshot_format_contract {
     }
 
     fn empty_snapshot_fixture() -> &'static str {
-        r#"TaskStore: 0 active task(s) (pending: 0, inprogress: 0)
+        r#"TaskStore: 0 task(s) (pending: 0, inprogress: 0, completed: 0)
 
 ```json
 {
diff --git a/crates/worker/src/feature/builtin/task/mod.rs b/crates/worker/src/feature/builtin/task/mod.rs
index 57c5e414..c0317983 100644
--- a/crates/worker/src/feature/builtin/task/mod.rs
+++ b/crates/worker/src/feature/builtin/task/mod.rs
@@ -15,8 +15,10 @@ mod store;
 mod tool_impl;
 
 pub(crate) use self::tool_impl::task_tools;
+#[cfg(test)]
+pub(crate) use store::TaskStatus;
 use store::snapshot_overview;
-pub(crate) use store::{TaskEntry, TaskStatus, TaskStore};
+pub(crate) use store::{TaskEntry, TaskStore};
 
 use crate::feature::{
     FeatureDescriptor, FeatureHookPoint, FeatureInstallContext, FeatureInstallError, FeatureModule,
@@ -76,7 +78,7 @@ impl TaskFeature {
     /// pointing at the same feature-owned store after rewind.
     pub fn restore_from_history(&self, history: &[Item]) {
         let restored = TaskStore::from_history(history);
-        self.state.task_store.replace_with(restored.list_active());
+        self.state.task_store.replace_with(restored.list());
     }
 
     /// Feature-owned snapshot text used by compaction to preserve Task state.
@@ -86,7 +88,7 @@ impl TaskFeature {
 
     /// Feature-owned compact summary used for the synthetic TaskList result.
     pub fn snapshot_overview(&self) -> String {
-        snapshot_overview(&self.state.task_store.list_active())
+        snapshot_overview(&self.state.task_store.list())
     }
 
     #[cfg(test)]
@@ -208,14 +210,8 @@ struct TaskReminderPreRequestHook {
 #[async_trait]
 impl Hook<PreLlmRequest> for TaskReminderPreRequestHook {
     async fn call(&self, input: &PreRequestContext) -> HookPreRequestAction {
-        let active_tasks: Vec<TaskEntry> = self
-            .state
-            .task_store
-            .list()
-            .into_iter()
-            .filter(|task| matches!(task.status, TaskStatus::Pending | TaskStatus::Inprogress))
-            .collect();
-        if active_tasks.is_empty() {
+        let tasks = self.state.task_store.list();
+        if tasks.is_empty() {
             return HookPreRequestAction::Continue;
         }
 
@@ -228,7 +224,7 @@ impl Hook<PreLlmRequest> for TaskReminderPreRequestHook {
 
         if let Some(system_items) = input.system_items() {
             self.state.reminder_state.note_reminder();
-            system_items.append_task_reminder(render_task_reminder_body(&active_tasks));
+            system_items.append_task_reminder(render_task_reminder_body(&tasks));
         }
         HookPreRequestAction::Continue
     }
@@ -252,11 +248,11 @@ fn is_task_management_tool(name: &str) -> bool {
     TASK_MANAGEMENT_TOOL_NAMES.contains(&name)
 }
 
-fn render_task_reminder_body(active_tasks: &[TaskEntry]) -> String {
+fn render_task_reminder_body(tasks: &[TaskEntry]) -> String {
     let mut body = String::from(
-        "Active session tasks are still open. If progress changed, call TaskUpdate.\n",
+        "Current session steps are listed below. Call TaskUpdate at each natural boundary: keep the current step inprogress, mark it completed when finished, and delete older completed steps once their result is no longer useful context.\n",
     );
-    for task in active_tasks {
+    for task in tasks {
         body.push_str(&format!(
             "- taskid {} ({}) {}\n",
             task.taskid, task.status, task.subject
@@ -433,7 +429,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn task_reminder_is_silent_when_no_active_tasks_exist() {
+    async fn task_reminder_includes_completed_tasks_until_deleted() {
         let feature = TaskFeature::new();
         let done = feature
             .task_store()
@@ -448,10 +444,16 @@ mod tests {
         };
         let pending = Arc::new(Mutex::new(Vec::new()));
 
-        for _ in 0..TASK_REMINDER_REQUEST_THRESHOLD * 2 {
+        for _ in 0..TASK_REMINDER_REQUEST_THRESHOLD {
             let _ = hook.call(&pre_request_context(Arc::clone(&pending))).await;
-            assert!(pending.lock().expect("pending queue poisoned").is_empty());
         }
+        let queued = pending.lock().expect("pending queue poisoned");
+        assert_eq!(queued.len(), 1);
+        let SystemItem::TaskReminder { body, .. } = &queued[0] else {
+            panic!("unexpected system item: {:?}", queued[0]);
+        };
+        assert!(body.contains("taskid 1 (completed) done"));
+        assert!(body.contains("delete older completed steps"));
     }
 
     #[tokio::test]
diff --git a/crates/worker/src/feature/builtin/task/store.rs b/crates/worker/src/feature/builtin/task/store.rs
index 740b4d16..d341811f 100644
--- a/crates/worker/src/feature/builtin/task/store.rs
+++ b/crates/worker/src/feature/builtin/task/store.rs
@@ -19,8 +19,8 @@ pub enum TaskStatus {
 }
 
 impl TaskStatus {
-    pub fn is_active(self) -> bool {
-        matches!(self, Self::Pending | Self::Inprogress)
+    pub fn is_retained(self) -> bool {
+        !matches!(self, Self::Deleted)
     }
 }
 
@@ -93,13 +93,6 @@ impl TaskStore {
             .clone()
     }
 
-    pub fn list_active(&self) -> Vec<TaskEntry> {
-        self.list()
-            .into_iter()
-            .filter(|task| task.status.is_active())
-            .collect()
-    }
-
     pub fn get(&self, taskid: u64) -> Option<TaskEntry> {
         self.inner
             .lock()
@@ -137,7 +130,7 @@ impl TaskStore {
             task.description = description;
         }
         let updated = task.clone();
-        if !updated.status.is_active() {
+        if !updated.status.is_retained() {
             inner.tasks.remove(task_position);
         }
         Ok(updated)
@@ -149,7 +142,7 @@ impl TaskStore {
 
     pub fn snapshot_limited(&self, limit: usize) -> TaskSnapshot {
         TaskSnapshot {
-            tasks: self.list_active().into_iter().take(limit).collect(),
+            tasks: self.list().into_iter().take(limit).collect(),
         }
     }
 
@@ -196,7 +189,7 @@ impl TaskStore {
     pub fn replace_with(&self, tasks: Vec<TaskEntry>) {
         let tasks: Vec<_> = tasks
             .into_iter()
-            .filter(|task| task.status.is_active())
+            .filter(|task| task.status.is_retained())
             .collect();
         let next_taskid = tasks
             .iter()
@@ -267,24 +260,30 @@ pub fn snapshot_overview(tasks: &[TaskEntry]) -> String {
         .iter()
         .filter(|t| t.status == TaskStatus::Inprogress)
         .count();
-    let active = pending + inprogress;
-    format!("TaskStore: {active} active task(s) (pending: {pending}, inprogress: {inprogress})")
+    let completed = tasks
+        .iter()
+        .filter(|t| t.status == TaskStatus::Completed)
+        .count();
+    format!(
+        "TaskStore: {} task(s) (pending: {pending}, inprogress: {inprogress}, completed: {completed})",
+        tasks.len()
+    )
 }
 
 pub fn render_snapshot(tasks: &[TaskEntry]) -> String {
-    let active_tasks: Vec<_> = tasks
+    let retained_tasks: Vec<_> = tasks
         .iter()
-        .filter(|task| task.status.is_active())
+        .filter(|task| task.status.is_retained())
         .cloned()
         .collect();
     let snapshot = TaskSnapshot {
-        tasks: active_tasks.clone(),
+        tasks: retained_tasks.clone(),
     };
     let json =
         serde_json::to_string_pretty(&snapshot).unwrap_or_else(|_| String::from("{\"tasks\":[]}"));
     format!(
         "{}\n\n```json\n{}\n```\n",
-        snapshot_overview(&active_tasks),
+        snapshot_overview(&retained_tasks),
         json
     )
 }
@@ -303,7 +302,7 @@ pub(super) fn parse_compact_snapshot_text(text: &str) -> Option<Vec<TaskEntry>>
         snapshot
             .tasks
             .into_iter()
-            .filter(|task| task.status.is_active())
+            .filter(|task| task.status.is_retained())
             .collect(),
     )
 }
@@ -312,6 +311,22 @@ pub(super) fn parse_compact_snapshot_text(text: &str) -> Option<Vec<TaskEntry>>
 mod tests {
     use super::*;
 
+    #[test]
+    fn completed_task_is_retained_until_deleted() {
+        let store = TaskStore::new();
+        store.create("step".into(), "description".into());
+        store
+            .update(1, Some(TaskStatus::Completed), None, None)
+            .unwrap();
+        assert_eq!(store.list()[0].status, TaskStatus::Completed);
+
+        let deleted = store
+            .update(1, Some(TaskStatus::Deleted), None, None)
+            .unwrap();
+        assert_eq!(deleted.status, TaskStatus::Deleted);
+        assert!(store.list().is_empty());
+    }
+
     #[test]
     fn replay_history_reconstructs_store_and_ignores_malformed_calls() {
         let history = vec![
@@ -323,9 +338,11 @@ mod tests {
         ];
         let store = TaskStore::from_history(&history);
         let tasks = store.list();
-        assert_eq!(tasks.len(), 1);
+        assert_eq!(tasks.len(), 2);
         assert_eq!(tasks[0].taskid, 1);
         assert_eq!(tasks[0].status, TaskStatus::Pending);
+        assert_eq!(tasks[1].taskid, 2);
+        assert_eq!(tasks[1].status, TaskStatus::Completed);
     }
 
     /// Wrap snapshot text the way `Worker::try_pre_run_compact` does, so tests
@@ -333,7 +350,7 @@ mod tests {
     fn wrap_snapshot_system_message(snapshot: &str) -> String {
         format!(
             "[Session TaskStore snapshot]\n\n{snapshot}\n\n\
-             This is the active session task list preserved across compaction. \
+             This is the retained session task list preserved across compaction. \
              The following TaskList tool result presents the same state through the tool lane."
         )
     }
@@ -355,9 +372,11 @@ mod tests {
         ];
         let store = TaskStore::from_history(&history);
         let tasks = store.list();
-        assert_eq!(tasks.len(), 1);
-        assert_eq!(tasks[0].taskid, 2);
-        assert_eq!(tasks[0].subject, "new");
+        assert_eq!(tasks.len(), 2);
+        assert_eq!(tasks[0].taskid, 1);
+        assert_eq!(tasks[0].status, TaskStatus::Completed);
+        assert_eq!(tasks[1].taskid, 2);
+        assert_eq!(tasks[1].subject, "new");
     }
 
     #[test]
@@ -396,12 +415,15 @@ mod tests {
         ];
         let store = TaskStore::from_history(&history);
         let tasks = store.list();
-        assert_eq!(tasks.len(), 2);
-        assert_eq!(tasks[0].taskid, 2);
-        assert_eq!(tasks[0].subject, "B");
-        assert_eq!(tasks[0].status, TaskStatus::Inprogress);
-        assert_eq!(tasks[1].taskid, 3);
-        assert_eq!(tasks[1].subject, "C");
+        assert_eq!(tasks.len(), 3);
+        assert_eq!(tasks[0].taskid, 1);
+        assert_eq!(tasks[0].subject, "A");
+        assert_eq!(tasks[0].status, TaskStatus::Completed);
+        assert_eq!(tasks[1].taskid, 2);
+        assert_eq!(tasks[1].subject, "B");
+        assert_eq!(tasks[1].status, TaskStatus::Inprogress);
+        assert_eq!(tasks[2].taskid, 3);
+        assert_eq!(tasks[2].subject, "C");
     }
 
     #[test]
@@ -443,10 +465,10 @@ mod tests {
         let snapshot_text = pre.snapshot_text();
         let system = Item::system_message(wrap_snapshot_system_message(&snapshot_text));
         let call = Item::tool_call("compact-tasklist", "TaskList", "{}");
-        let active_tasks = pre.list_active();
+        let retained_tasks = pre.list();
         let result = Item::tool_result_with_content(
             "compact-tasklist",
-            snapshot_overview(&active_tasks),
+            snapshot_overview(&retained_tasks),
             snapshot_text.clone(),
         );
 
@@ -455,7 +477,7 @@ mod tests {
             .as_text()
             .and_then(parse_compact_snapshot_text)
             .expect("system message should parse as snapshot");
-        assert_eq!(extracted, active_tasks);
+        assert_eq!(extracted, retained_tasks);
 
         // The synthetic call/result pair shares one call_id and carries the
         // expected tool name + detailed content.
@@ -482,6 +504,6 @@ mod tests {
 
         // Replaying the full triple reconstructs the same TaskStore.
         let store = TaskStore::from_history(&[system, call, result]);
-        assert_eq!(store.list(), active_tasks);
+        assert_eq!(store.list(), retained_tasks);
     }
 }
diff --git a/crates/worker/src/feature/builtin/task/tool_impl.rs b/crates/worker/src/feature/builtin/task/tool_impl.rs
index f733dc48..931ccbea 100644
--- a/crates/worker/src/feature/builtin/task/tool_impl.rs
+++ b/crates/worker/src/feature/builtin/task/tool_impl.rs
@@ -18,7 +18,7 @@ struct TaskCreateParams {
 
 #[derive(Debug, Deserialize, schemars::JsonSchema)]
 struct TaskListParams {
-    /// Maximum number of active tasks to return. Defaults to 20.
+    /// Maximum number of retained tasks to return. Defaults to 20.
     #[serde(default)]
     limit: Option<usize>,
 }
@@ -55,23 +55,28 @@ struct TaskUpdateTool {
     store: TaskStore,
 }
 
-const CREATE_DESCRIPTION: &str = "Create a session-lifetime task only when user-visible \
-progress tracking is genuinely useful: multiple active tasks must be remembered, or the work \
-will involve long edits, long-running commands, extended investigation, or interruption-prone \
-coordination. Do not create a task just because a request has several steps, and do not create \
-one for short questions, quick checks, single reviews, or one-off commands. Prefer updating an \
-existing active task over creating a duplicate. Input only `subject` and `description`; `taskid` \
-is assigned automatically and initial `status` is `pending`.";
-const LIST_DESCRIPTION: &str = "List active session-lifetime tasks. Completed and deleted tasks are forgotten and omitted. Defaults to 20 tasks unless `limit` is provided.";
+const CREATE_DESCRIPTION: &str = "Before beginning nontrivial work, decompose the predictable \
+portion into a small ordered set of natural, user-visible steps and create one session-lifetime task \
+per step. A natural step has a distinct verifiable outcome, such as investigation, implementation, \
+or validation; do not create a task for every command or mechanical substep. Do not collapse several \
+predictable steps into one umbrella task. Keep future steps pending, mark the current step inprogress, \
+and add or revise tasks when new information changes the plan. Skip task tracking for short questions, \
+quick checks, and one-off commands. Input only `subject` and `description`; `taskid` is assigned \
+automatically and initial `status` is `pending`.";
+const LIST_DESCRIPTION: &str = "List retained session-lifetime tasks, including completed steps that \
+have not yet been deleted. Deleted tasks are forgotten and omitted. Defaults to 20 tasks unless \
+`limit` is provided.";
 const GET_DESCRIPTION: &str = "Get one session-lifetime task by `taskid`. Tasks are \
 user-visible real-time status for short-term current-work tracking. Returns an error if the task \
 does not exist.";
-const UPDATE_DESCRIPTION: &str = "Update an existing session-lifetime task when meaningful \
-progress changes between substantial steps. Tasks are user-visible real-time status, so avoid \
-churn for trivial substeps. Keep status current with `pending`, `inprogress`, `completed`, or \
-`deleted`. Provide `taskid` and at least one of `status`, `subject`, or `description`; deletion is \
-logical (`status = deleted`). If an unexpected problem blocks progress, do not force the next \
-step: leave the task as-is, summarize the problem to the user, and end the turn.";
+const UPDATE_DESCRIPTION: &str = "Update task status at each natural step boundary. Mark the \
+finished current step completed before advancing the next pending step to inprogress. Completed tasks \
+remain visible as recent workflow context; at a later natural boundary, delete older completed tasks \
+whose result is no longer useful. Do not jump directly from active to deleted merely to hide progress, \
+and avoid churn for mechanical substeps. Keep status current with `pending`, `inprogress`, `completed`, \
+or `deleted`. Provide `taskid` and at least one of `status`, `subject`, or `description`; deletion is \
+logical (`status = deleted`). If an unexpected problem blocks progress, do not force the next step: \
+leave the task as-is, summarize the problem to the user, and end the turn.";
 
 #[async_trait]
 impl Tool for TaskCreateTool {
@@ -83,7 +88,7 @@ impl Tool for TaskCreateTool {
         let params: TaskCreateParams = serde_json::from_str(input_json)
             .map_err(|e| ToolError::InvalidArgument(format!("invalid TaskCreate input: {e}")))?;
         let created = self.store.create(params.subject, params.description);
-        let tasks = self.store.list_active();
+        let tasks = self.store.list();
         Ok(task_output(
             format!(
                 "Created task {} ({})\n{}",
@@ -106,10 +111,10 @@ impl Tool for TaskListTool {
         let params: TaskListParams = serde_json::from_str(input_json)
             .map_err(|e| ToolError::InvalidArgument(format!("invalid TaskList input: {e}")))?;
         let limit = params.limit.unwrap_or(DEFAULT_TASK_LIST_LIMIT);
-        let active_tasks = self.store.list_active();
-        let tasks: Vec<_> = active_tasks.iter().take(limit).cloned().collect();
+        let retained_tasks = self.store.list();
+        let tasks: Vec<_> = retained_tasks.iter().take(limit).cloned().collect();
         Ok(ToolOutput {
-            summary: list_overview(active_tasks.len(), tasks.len()),
+            summary: list_overview(retained_tasks.len(), tasks.len()),
             content: Some(render_task_list(&tasks)),
 
             attachments: Vec::new(),
@@ -157,7 +162,7 @@ impl Tool for TaskUpdateTool {
                 params.description,
             )
             .map_err(|e| ToolError::ExecutionFailed(e.to_string()))?;
-        let tasks = self.store.list_active();
+        let tasks = self.store.list();
         Ok(task_output(
             format!(
                 "Updated task {} ({})\n{}",
@@ -179,14 +184,14 @@ fn task_output(summary: String, task: &TaskEntry) -> ToolOutput {
     }
 }
 
-fn list_overview(total_active: usize, returned: usize) -> String {
-    if returned < total_active {
+fn list_overview(total: usize, returned: usize) -> String {
+    if returned < total {
         format!(
-            "TaskStore: {returned} active task(s) shown; {} omitted.",
-            total_active - returned
+            "TaskStore: {returned} task(s) shown; {} omitted.",
+            total - returned
         )
     } else {
-        format!("TaskStore: {returned} active task(s)")
+        format!("TaskStore: {returned} task(s)")
     }
 }
 
@@ -310,7 +315,7 @@ mod tests {
         assert!(out.content.unwrap().contains("implement tasks"));
 
         let out = list.execute("{}", Default::default()).await.unwrap();
-        assert!(out.summary.contains("1 active task(s)"));
+        assert!(out.summary.contains("1 task(s)"));
         let content = out.content.unwrap();
         assert!(content.contains("\"taskid\": 1"));
         assert!(!content.contains("\"limit\""));
@@ -318,7 +323,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn task_list_omits_completed_deleted_and_defaults_to_twenty() {
+    async fn task_list_retains_completed_omits_deleted_and_defaults_to_twenty() {
         let store = TaskStore::new();
         let create = tool(task_create_tool(store.clone()));
         let update = tool(task_update_tool(store.clone()));
@@ -343,10 +348,7 @@ mod tests {
             .unwrap();
 
         let out = list.execute("{}", Default::default()).await.unwrap();
-        assert_eq!(
-            out.summary,
-            "TaskStore: 20 active task(s) shown; 3 omitted."
-        );
+        assert_eq!(out.summary, "TaskStore: 20 task(s) shown; 4 omitted.");
         let content = out.content.unwrap();
         let json: serde_json::Value = serde_json::from_str(&content).unwrap();
         let tasks = json.as_array().unwrap();
@@ -355,7 +357,7 @@ mod tests {
             .iter()
             .map(|task| task["taskid"].as_u64().unwrap())
             .collect();
-        assert!(!ids.contains(&1));
+        assert!(ids.contains(&1));
         assert!(!ids.contains(&2));
         assert!(!content.contains("\"limit\""));
         assert!(!content.contains("\"total_active\""));
@@ -365,10 +367,7 @@ mod tests {
             .execute(r#"{"limit":3}"#, Default::default())
             .await
             .unwrap();
-        assert_eq!(
-            out.summary,
-            "TaskStore: 3 active task(s) shown; 20 omitted."
-        );
+        assert_eq!(out.summary, "TaskStore: 3 task(s) shown; 21 omitted.");
         let content = out.content.unwrap();
         let json: serde_json::Value = serde_json::from_str(&content).unwrap();
         assert_eq!(json.as_array().unwrap().len(), 3);
@@ -412,6 +411,16 @@ mod tests {
         assert!(!content.contains("completed task"));
     }
 
+    #[test]
+    fn task_descriptions_require_natural_steps_and_completed_cleanup() {
+        assert!(CREATE_DESCRIPTION.contains("Before beginning nontrivial work"));
+        assert!(CREATE_DESCRIPTION.contains("one session-lifetime task per step"));
+        assert!(CREATE_DESCRIPTION.contains("Do not collapse several predictable steps"));
+        assert!(UPDATE_DESCRIPTION.contains("each natural step boundary"));
+        assert!(UPDATE_DESCRIPTION.contains("remain visible"));
+        assert!(UPDATE_DESCRIPTION.contains("delete older completed tasks"));
+    }
+
     #[tokio::test]
     async fn task_update_validates_existing_and_at_least_one_field() {
         let store = TaskStore::new();
diff --git a/crates/worker/src/worker.rs b/crates/worker/src/worker.rs
index bab0c157..2b333b7c 100644
--- a/crates/worker/src/worker.rs
+++ b/crates/worker/src/worker.rs
@@ -3347,7 +3347,7 @@ impl<C: LlmClient, St: Store> Worker<C, St> {
         }
         let task_snapshot_message = Item::system_message(format!(
             "[Session TaskStore snapshot]\n\n{task_snapshot_text}\n\n\
-             This is the active session task list preserved across compaction. \
+             This is the retained session task list preserved across compaction. \
              The following TaskList tool result presents the same state through the tool lane."
         ));
         compact_introduced_system_messages.push(task_snapshot_message.clone());
diff --git a/web/workspace/src/lib/workspace/console/tasks.test.ts b/web/workspace/src/lib/workspace/console/tasks.test.ts
index 084453c8..ac7870bb 100644
--- a/web/workspace/src/lib/workspace/console/tasks.test.ts
+++ b/web/workspace/src/lib/workspace/console/tasks.test.ts
@@ -53,7 +53,7 @@ Deno.test("TaskCreate and TaskUpdate mirror the active TUI task store", () => {
   assert(counts.inprogress === 1, "one task should be in progress");
 });
 
-Deno.test("completed and deleted tasks remain in the TUI-style store", () => {
+Deno.test("completed tasks remain visible until explicitly deleted", () => {
   let state = emptyConsoleTaskState();
   for (const subject of ["complete", "delete"]) {
     state = applyTaskToolCall(
@@ -72,14 +72,11 @@ Deno.test("completed and deleted tasks remain in the TUI-style store", () => {
     "TaskUpdate",
     JSON.stringify({ taskid: 2, status: "deleted" }),
   );
-  assert(
-    state.tasks.length === 2,
-    "the full TaskStore should retain inactive tasks",
-  );
+  assert(state.tasks.length === 1, "only deleted tasks should be forgotten");
   const counts = taskCounts(state.tasks);
   assert(counts.completed === 1, "completed tasks should remain counted");
-  assert(counts.deleted === 1, "deleted tasks should remain counted");
-  assert(counts.active === 0, "inactive tasks should not be shown as active");
+  assert(counts.deleted === 0, "deleted tasks should be forgotten");
+  assert(counts.active === 0, "completed tasks should not be shown as active");
 });
 
 Deno.test("session TaskStore snapshot replaces stale state and advances ids", () => {
@@ -102,13 +99,13 @@ TaskStore: 1 active task(s) (pending: 0, inprogress: 1)
 \`\`\`
 `;
   state = applyTaskSnapshotText(state, snapshot);
+  assert(state.tasks.length === 2, "snapshot should restore retained tasks");
+  assert(state.tasks[0].taskid === 4, "the completed task should be restored");
+  assert(state.tasks[1].taskid === 7, "the active task should be restored");
   assert(
-    state.tasks.length === 2,
-    "snapshot should restore the full TaskStore",
+    state.nextTaskId === 8,
+    "next id should follow the highest retained task id",
   );
-  assert(state.tasks[0].taskid === 4, "completed tasks should remain restored");
-  assert(state.tasks[1].taskid === 7, "active tasks should remain restored");
-  assert(state.nextTaskId === 8, "next id should follow the highest task id");
   state = applyTaskToolCall(
     state,
     "TaskCreate",
diff --git a/web/workspace/src/lib/workspace/console/tasks.ts b/web/workspace/src/lib/workspace/console/tasks.ts
index 8a0fc114..d0b6e606 100644
--- a/web/workspace/src/lib/workspace/console/tasks.ts
+++ b/web/workspace/src/lib/workspace/console/tasks.ts
@@ -62,6 +62,13 @@ export function applyTaskToolCall(
 
   const current = state.tasks[index];
   const status = update.status ?? current.status;
+  if (status === "deleted") {
+    return {
+      tasks: state.tasks.filter((_, taskIndex) => taskIndex !== index),
+      nextTaskId: state.nextTaskId,
+    };
+  }
+
   const tasks = [...state.tasks];
   tasks[index] = {
     taskid: current.taskid,
@@ -78,9 +85,10 @@ export function applyTaskSnapshotText(
 ): ConsoleTaskState {
   const tasks = parseTaskSnapshotText(text);
   if (!tasks) return state;
+  const retained = tasks.filter((task) => task.status !== "deleted");
   return {
-    tasks,
-    nextTaskId: Math.max(1, ...tasks.map((task) => task.taskid + 1)),
+    tasks: retained,
+    nextTaskId: Math.max(1, ...retained.map((task) => task.taskid + 1)),
   };
 }
 
@@ -105,7 +113,9 @@ export function parseTaskSnapshotText(text: string): ConsoleTask[] | null {
   for (const candidate of value.tasks) {
     const task = taskEntry(candidate);
     if (!task) return null;
-    tasks.push(task);
+    if (task.status !== "deleted") {
+      tasks.push(task);
+    }
   }
   return tasks;
 }