Count the tool conversation while it is in flight

app/MindWork AI Studio/Chat/ContentText.cs

@@ -55,6 +55,49 @@ public sealed class ContentText : IContent
     [JsonIgnore]
     public ToolRuntimeStatus ToolRuntimeStatus { get; set; } = new();
 
+    /// <summary>
+    /// What the tool conversation of the running request adds to it, as far as it has got.
+    /// </summary>
+    /// <remarks>
+    /// A model which calls tools asks several times before it answers, and every one of those
+    /// requests carries everything the tools returned so far -- up to three hundred thousand
+    /// characters of it. None of that is in this block's text, and none of it is in the traces
+    /// either: those say what happened, not what it costs. So it is kept here, where whoever
+    /// counts the conversation walks past anyway.<br/><br/>
+    /// Replaced as a whole, never appended to: it is written by the thread which runs the tools
+    /// and read by the one which renders, and an exchange leaves the reader with a list which was
+    /// true at some moment rather than with one being rewritten under it.<br/><br/>
+    /// Gone when the answer is there, and never persisted. The accumulated tool conversation lives
+    /// in the provider adapter, which is created for one request and dropped with it -- so the next
+    /// request does not carry it, and a number which still counted it would promise a cost nobody
+    /// is going to pay.
+    /// </remarks>
+    [JsonIgnore]
+    public IReadOnlyList<string> PendingToolConversation { get; set; } = [];
+
+    /// <summary>
+    /// Clears what the previous run of the tools left behind.
+    /// </summary>
+    /// <remarks>
+    /// Both parts at once, because both belong to one request: the traces the user reads and the
+    /// payload the counting needs. They were cleared separately for exactly as long as there was
+    /// only one of them.
+    /// </remarks>
+    public void BeginToolRun()
+    {
+        this.ToolInvocations.Clear();
+        this.PendingToolConversation = [];
+    }
+
+    /// <summary>
+    /// Says that no request is running anymore.
+    /// </summary>
+    /// <remarks>
+    /// The traces stay -- they are what the user reads afterwards to see how the answer came
+    /// about. What goes is the payload, which belonged to a request that is over.
+    /// </remarks>
+    public void EndToolRun() => this.PendingToolConversation = [];
+
     /// <inheritdoc />
     public async Task<ChatThread> CreateFromProviderAsync(IProvider provider, Model chatModel, IContent? lastUserPrompt, ChatThread? chatThread, CancellationToken token = default)
     {
@@ -177,7 +220,8 @@ public sealed class ContentText : IContent
         finally
         {
             this.Text = this.Text.RemoveThinkTags().Trim();
-        
+            this.EndToolRun();
+
             // Inform the UI that the streaming is done:
             await this.StreamingDone();
         }

app/MindWork AI Studio/Chat/ConversationParts.cs

@@ -9,6 +9,11 @@ namespace AIStudio.Chat;
 /// sends: the system prompt, the text of every block, and the attachments hanging off those
 /// blocks -- plus whatever is standing in the composer but has not been sent yet, because that is
 /// the part a person is deciding about while they look at the number.
+///
+/// And, while a request is running, what its tools have returned so far. That is the one part
+/// which is not about the next request but about the one in flight: it is what the model is
+/// reading at this moment, it is what fills the window while somebody watches, and it is gone
+/// again once the answer stands.
 /// </remarks>
 public sealed record ConversationParts
 {
@@ -23,13 +28,17 @@ public sealed record ConversationParts
     public IReadOnlyList<string> Texts { get; init; } = [];
 
     /// <summary>
-    /// The texts which are still being written.
+    /// The texts which belong to this moment alone.
     /// </summary>
     /// <remarks>
     /// They cost exactly what the others cost; what sets them apart is that they will never be seen
     /// again in this shape. The sentence somebody is typing changes with the next pause, and an
     /// answer being streamed is a different text three seconds later -- so remembering what they
     /// cost fills memory with answers nobody will ask for again.
+    ///
+    /// What a model's tools have returned so far belongs here for the same reason, although nobody
+    /// is writing it: it travels with every further round of one request and with nothing after
+    /// that, so it is measured while it matters and forgotten when the answer is there.
     /// </remarks>
     public IReadOnlyList<string> GrowingTexts { get; init; } = [];
 
@@ -48,7 +57,9 @@ public sealed record ConversationParts
     /// </summary>
     /// <remarks>
     /// Blocks without text are skipped, because the message builder skips them too: a block whose
-    /// text is empty never becomes a message, whatever else hangs off it.
+    /// text is empty never becomes a message, whatever else hangs off it. What such a block may
+    /// still carry is the tool conversation of a request which is running right now -- that one
+    /// does travel, and it is read before the text is looked at.
     /// </remarks>
     /// <param name="thread">The conversation so far, or null when there is none yet.</param>
     /// <param name="systemPrompt">
@@ -79,7 +90,18 @@ public sealed record ConversationParts
             //
             foreach (var block in thread.Blocks)
             {
-                if (block.ContentType is not ContentType.TEXT || block.Content is not ContentText text || string.IsNullOrWhiteSpace(text.Text))
+                if (block.ContentType is not ContentType.TEXT || block.Content is not ContentText text)
+                    continue;
+
+                //
+                // Asked before the text is, because while a model calls tools there is no text yet:
+                // the answer arrives in one piece at the end, and everything in between travels as
+                // the tool conversation. A block skipped for having nothing to say is exactly the
+                // block whose request is growing the fastest.
+                //
+                growing.AddRange(text.PendingToolConversation);
+
+                if (string.IsNullOrWhiteSpace(text.Text))
                     continue;
 
                 if (text.IsStreaming)