fix(worker): make list_tasks/batch_get_tasks lean by default

list_tasks on a list of ~100 verbosely-described tasks could return
390k+ characters in one call, blowing past the caller's token limit.
Both tools now default to lean TaskRefDto references (no
Description/Result) and take an includeDescription flag to opt back
into the full TaskDto payload — same flag-alongside-nullable-payload
idiom already used by BatchGetTaskResult/TaskConfigResult. get_task is
unchanged.

tests/ClaudeDo.Worker.Tests/External/BatchMcpToolsTests.cs

@@ -149,17 +149,55 @@ public sealed class BatchMcpToolsTests : IDisposable
         var task = await SeedTaskAsync(listId);
         var sut = BuildSut();
 
-        var results = await sut.BatchGetTasks(new[] { task.Id, "nope" }, CancellationToken.None);
+        var results = await sut.BatchGetTasks(new[] { task.Id, "nope" }, cancellationToken: CancellationToken.None);
 
         var found = results.Single(r => r.Id == task.Id);
         var missing = results.Single(r => r.Id == "nope");
         Assert.True(found.Found);
         Assert.NotNull(found.Task);
+        Assert.Null(found.TaskFull);
         Assert.False(missing.Found);
         Assert.Null(missing.Task);
+        Assert.Null(missing.TaskFull);
         Assert.Null(missing.Error);
     }
 
+    [Fact]
+    public async Task BatchGetTasks_Default_ReturnsLeanTask_NoTaskFull()
+    {
+        var listId = await SeedListAsync();
+        var task = await SeedTaskAsync(listId);
+        task.Description = "a description that should not come back by default";
+        await _tasks.UpdateAsync(task);
+        var sut = BuildSut();
+
+        var results = await sut.BatchGetTasks(new[] { task.Id }, cancellationToken: CancellationToken.None);
+
+        var found = results.Single(r => r.Id == task.Id);
+        Assert.True(found.Found);
+        Assert.NotNull(found.Task);
+        Assert.Equal(task.Id, found.Task!.Id);
+        Assert.Null(found.TaskFull);
+    }
+
+    [Fact]
+    public async Task BatchGetTasks_IncludeDescriptionTrue_ReturnsTaskFull()
+    {
+        var listId = await SeedListAsync();
+        var task = await SeedTaskAsync(listId);
+        task.Description = "the full description";
+        await _tasks.UpdateAsync(task);
+        var sut = BuildSut();
+
+        var results = await sut.BatchGetTasks(new[] { task.Id }, includeDescription: true, cancellationToken: CancellationToken.None);
+
+        var found = results.Single(r => r.Id == task.Id);
+        Assert.True(found.Found);
+        Assert.Null(found.Task);
+        Assert.NotNull(found.TaskFull);
+        Assert.Equal("the full description", found.TaskFull!.Description);
+    }
+
     [Fact]
     public async Task BatchDeleteTasks_RunningTask_ReportedNotOk_OthersDeleted()
     {
@@ -212,7 +250,7 @@ public sealed class BatchMcpToolsTests : IDisposable
     {
         var sut = BuildSut();
         await Assert.ThrowsAsync<InvalidOperationException>(
-            () => sut.BatchGetTasks(Array.Empty<string>(), CancellationToken.None));
+            () => sut.BatchGetTasks(Array.Empty<string>(), cancellationToken: CancellationToken.None));
     }
 
     [Fact]
@@ -222,7 +260,7 @@ public sealed class BatchMcpToolsTests : IDisposable
         var ids = Enumerable.Range(0, 101).Select(i => i.ToString()).ToArray();
 
         var ex = await Assert.ThrowsAsync<InvalidOperationException>(
-            () => sut.BatchGetTasks(ids, CancellationToken.None));
+            () => sut.BatchGetTasks(ids, cancellationToken: CancellationToken.None));
         Assert.Contains("max", ex.Message, StringComparison.OrdinalIgnoreCase);
     }
 }

tests/ClaudeDo.Worker.Tests/External/ExternalMcpServiceTests.cs

@@ -947,10 +947,11 @@ public sealed class ExternalMcpServiceTests : IDisposable
         await SeedTaskAsync(listId, "idle", TaskStatus.Idle);
         var sut = NewService();
 
-        var result = await sut.ListTasks(listId, null, "WaitingForReview", CancellationToken.None);
+        var result = await sut.ListTasks(listId, null, "WaitingForReview", cancellationToken: CancellationToken.None);
 
-        Assert.Single(result);
-        Assert.Equal("WaitingForReview", result[0].Status);
+        Assert.NotNull(result.Tasks);
+        Assert.Single(result.Tasks!);
+        Assert.Equal("WaitingForReview", result.Tasks![0].Status);
     }
 
     [Fact]
@@ -961,10 +962,47 @@ public sealed class ExternalMcpServiceTests : IDisposable
         await SeedTaskAsync(listId, "done", TaskStatus.Done);
         var sut = NewService();
 
-        var result = await sut.ListTasks(listId, null, "WaitingForChildren", CancellationToken.None);
+        var result = await sut.ListTasks(listId, null, "WaitingForChildren", cancellationToken: CancellationToken.None);
 
-        Assert.Single(result);
-        Assert.Equal("WaitingForChildren", result[0].Status);
+        Assert.NotNull(result.Tasks);
+        Assert.Single(result.Tasks!);
+        Assert.Equal("WaitingForChildren", result.Tasks![0].Status);
+    }
+
+    [Fact]
+    public async Task ListTasks_Default_ReturnsLeanReferences_NoDescriptionOrTasksFull()
+    {
+        var listId = await SeedListAsync();
+        var task = await SeedTaskAsync(listId, "with desc");
+        task.Description = "a long description that should not come back by default";
+        await _tasks.UpdateAsync(task);
+        var sut = NewService();
+
+        var result = await sut.ListTasks(listId, cancellationToken: CancellationToken.None);
+
+        Assert.False(result.IncludeDescription);
+        Assert.NotNull(result.Tasks);
+        Assert.Null(result.TasksFull);
+        Assert.Single(result.Tasks!);
+        Assert.Equal(task.Id, result.Tasks![0].Id);
+    }
+
+    [Fact]
+    public async Task ListTasks_IncludeDescriptionTrue_ReturnsFullTasks()
+    {
+        var listId = await SeedListAsync();
+        var task = await SeedTaskAsync(listId, "with desc");
+        task.Description = "the full description";
+        await _tasks.UpdateAsync(task);
+        var sut = NewService();
+
+        var result = await sut.ListTasks(listId, includeDescription: true, cancellationToken: CancellationToken.None);
+
+        Assert.True(result.IncludeDescription);
+        Assert.Null(result.Tasks);
+        Assert.NotNull(result.TasksFull);
+        Assert.Single(result.TasksFull!);
+        Assert.Equal("the full description", result.TasksFull![0].Description);
     }
 
     // ── MergeTask allowWaitingForReview ───────────────────────────────────────