feat(notes): add_note MCP tool with a per-day agent cap

Agents can write into the user's daily notes, but only within limits:
max 10 agent notes a day, max 500 characters, add only — no edit, no
delete. A new from_agent column separates their lines from the user's
so the cap counts the right ones and the UI can mark them.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/ClaudeDo.Worker/External/NotesMcpTools.cs

@@ -0,0 +1,59 @@
+using System.ComponentModel;
+using ClaudeDo.Data.Repositories;
+using ClaudeDo.Worker.Hub;
+using ModelContextProtocol.Server;
+
+namespace ClaudeDo.Worker.External;
+
+public sealed record AddNoteResult(bool Saved, string Id, int AgentNotesToday, int RemainingToday);
+
+[McpServerToolType]
+public sealed class NotesMcpTools
+{
+    /// <summary>Agent-written notes allowed per day. The user's own notes are never counted or
+    /// capped — this only stops an agent from burying the day in its own bullets.</summary>
+    public const int DailyAgentCap = 10;
+
+    /// <summary>A note is a line, not a report. Longer output belongs in a task or a finding.</summary>
+    public const int MaxLength = 500;
+
+    private readonly DailyNoteRepository _notes;
+    private readonly HubBroadcaster _broadcaster;
+
+    public NotesMcpTools(DailyNoteRepository notes, HubBroadcaster broadcaster)
+    {
+        _notes = notes;
+        _broadcaster = broadcaster;
+    }
+
+    [McpServerTool, Description(
+        "Add one short line to the user's notes for today — the day log they read in ClaudeDo, " +
+        "not a log for you. Write only what the user would want to reread later and would " +
+        "otherwise lose: a decision they made, something you found that changes their plans, " +
+        "something they asked you to remember for the day. Task status, your progress and " +
+        "anything already visible in the task list are noise here. When unsure, don't. " +
+        "Capped at 10 agent notes per day; you cannot edit or delete notes, so a bad one stays " +
+        "until the user removes it.")]
+    public async Task<AddNoteResult> AddNote(
+        [Description("The note itself: one plain sentence, no markdown, no prefix, max 500 characters.")] string text,
+        CancellationToken cancellationToken = default)
+    {
+        var trimmed = (text ?? "").Trim();
+        if (trimmed.Length == 0)
+            throw new InvalidOperationException("text is required.");
+        if (trimmed.Length > MaxLength)
+            throw new InvalidOperationException(
+                $"Note is {trimmed.Length} characters, the limit is {MaxLength}. Shorten it to one line.");
+
+        var today = DateOnly.FromDateTime(DateTime.Today);
+        var used = await _notes.CountAgentNotesAsync(today, cancellationToken);
+        if (used >= DailyAgentCap)
+            throw new InvalidOperationException(
+                $"Daily cap reached: {DailyAgentCap} agent notes already written today. " +
+                "Nothing was saved — tell the user instead of retrying.");
+
+        var note = await _notes.AddAsync(today, trimmed, fromAgent: true, cancellationToken);
+        await _broadcaster.NotesUpdated();
+        return new AddNoteResult(true, note.Id, used + 1, DailyAgentCap - used - 1);
+    }
+}

src/ClaudeDo.Worker/Hub/HubBroadcaster.cs

@@ -37,6 +37,10 @@ public sealed class HubBroadcaster : IPrimeBroadcaster, IRefineBroadcaster
     public Task HandoffRequested(string taskId, IReadOnlyList<string> survivingTaskIds, string nextPhase) =>
         _hub.Clients.All.SendAsync("HandoffRequested", taskId, survivingTaskIds, nextPhase);
 
+    /// <summary>An agent wrote a note through MCP — the open notes editor reloads.</summary>
+    public Task NotesUpdated() =>
+        _hub.Clients.All.SendAsync("NotesUpdated");
+
     public Task ListUpdated(string listId) =>
         _hub.Clients.All.SendAsync("ListUpdated", listId);
 

src/ClaudeDo.Worker/Hub/WorkerHub.cs

@@ -970,14 +970,25 @@ public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
     {
         using var ctx = _dbFactory.CreateDbContext();
         var notes = await new DailyNoteRepository(ctx).ListByDayAsync(Day(dayIso));
-        return notes.Select(n => new DailyNoteDto(n.Id, n.Date.ToString("yyyy-MM-dd"), n.Text, n.SortOrder)).ToList();
+        return notes.Select(Dto).ToList();
     }
 
+    /// <summary>Both ends inclusive — the editor loads today plus its recent history in one call.</summary>
+    public async Task<List<DailyNoteDto>> GetDailyNotesBetween(string startIso, string endIso)
+    {
+        using var ctx = _dbFactory.CreateDbContext();
+        var notes = await new DailyNoteRepository(ctx).ListBetweenAsync(Day(startIso), Day(endIso));
+        return notes.Select(Dto).ToList();
+    }
+
+    private static DailyNoteDto Dto(Data.Models.DailyNoteEntity n) =>
+        new(n.Id, n.Date.ToString("yyyy-MM-dd"), n.Text, n.SortOrder, n.FromAgent);
+
     public async Task<DailyNoteDto> AddDailyNote(string dayIso, string text)
     {
         using var ctx = _dbFactory.CreateDbContext();
         var n = await new DailyNoteRepository(ctx).AddAsync(Day(dayIso), text);
-        return new DailyNoteDto(n.Id, n.Date.ToString("yyyy-MM-dd"), n.Text, n.SortOrder);
+        return Dto(n);
     }
 
     public async Task UpdateDailyNote(string id, string text)

src/ClaudeDo.Worker/Program.cs

@@ -355,7 +355,9 @@ if (cfg.ExternalMcpPort > 0)
     externalBuilder.Services.AddScoped<TaskWaitMcpTools>();
     externalBuilder.Services.AddScoped<QueueStateMcpTools>();
     externalBuilder.Services.AddScoped<AttachmentMcpTools>();
+    externalBuilder.Services.AddScoped<DailyNoteRepository>();
     externalBuilder.Services.AddScoped<FindingsMcpTools>();
+    externalBuilder.Services.AddScoped<NotesMcpTools>();
     externalBuilder.Services.AddMcpServer()
         .WithHttpTransport(o => o.Stateless = true)
         .WithRequestFilters(f => f.AddCallToolFilter(ExternalMcpExceptionFilter.Wrap))
@@ -371,7 +373,8 @@ if (cfg.ExternalMcpPort > 0)
         .WithTools<TaskWaitMcpTools>()
         .WithTools<QueueStateMcpTools>()
         .WithTools<AttachmentMcpTools>()
-        .WithTools<FindingsMcpTools>();
+        .WithTools<FindingsMcpTools>()
+        .WithTools<NotesMcpTools>();
     externalBuilder.WebHost.UseUrls($"http://127.0.0.1:{cfg.ExternalMcpPort}");
 
     externalApp = externalBuilder.Build();

src/ClaudeDo.Worker/Report/DailyNoteDto.cs

@@ -1,3 +1,3 @@
 namespace ClaudeDo.Worker.Report;
 
-public sealed record DailyNoteDto(string Id, string Date, string Text, int SortOrder);
+public sealed record DailyNoteDto(string Id, string Date, string Text, int SortOrder, bool FromAgent);