Improved the Web Based Harness

DebugTools/MccMcpWebPlayground/Harness/MccPromptComposer.cs

@@ -0,0 +1,86 @@
+namespace DebugTools.MccMcpWebPlayground.Harness;
+
+public sealed class MccPromptComposer
+{
+    private const string HarnessContract = """
+You are operating Minecraft Console Client through MCC MCP tools.
+
+Rules:
+- Use tool results and the run-state summary as the source of truth.
+- Execute tools sequentially.
+- End the run only with mcc_submit_final.
+- status=completed is valid only when no required verification obligations remain open.
+- If the task is blocked or partial, say exactly what is verified and what remains unverified.
+- Do not repeat the same failing stateful action with the same arguments.
+- mcc_quit_client requires explicit user intent.
+- Prefer structured high-level tools. Avoid escape hatches unless they are explicitly exposed and necessary.
+""";
+
+    public List<object> Compose(MccRunState runState)
+    {
+        List<object> messages =
+        [
+            BuildSystemMessage(HarnessContract),
+            BuildSystemMessage(runState.Guidance.SystemPrompt),
+            BuildSystemMessage(BuildStateSummary(runState)),
+            .. runState.BaseConversationMessages
+        ];
+
+        if (!string.IsNullOrWhiteSpace(runState.CompactionSummary))
+        {
+            messages.Add(BuildSystemMessage($"""
+Older verified evidence summary
+{runState.CompactionSummary}
+"""));
+        }
+
+        foreach (object message in runState.ToolConversationMessages.TakeLast(12))
+            messages.Add(message);
+
+        return messages;
+    }
+
+    private static Dictionary<string, object?> BuildSystemMessage(string text)
+    {
+        return new Dictionary<string, object?>
+        {
+            ["role"] = "system",
+            ["content"] = text
+        };
+    }
+
+    private static string BuildStateSummary(MccRunState runState)
+    {
+        string evidence = runState.Evidence.Count == 0
+            ? "- none yet"
+            : string.Join('\n', runState.Evidence.TakeLast(6).Select(record =>
+                $"- {record.Id} {record.ToolName}: {record.Summary}"));
+
+        string obligations = runState.OpenObligations.Count == 0
+            ? "- none"
+            : string.Join('\n', runState.OpenObligations.Select(obligation =>
+                $"- {obligation.Id} {obligation.ToolName}/{obligation.Kind}: {obligation.Description}"));
+
+        string bestPractices = runState.Guidance.BestPractices.Length == 0
+            ? "- use verified MCC state before claiming success"
+            : string.Join('\n', runState.Guidance.BestPractices.Take(4).Select(item => $"- {item}"));
+
+        return $"""
+Current run state
+- turnCount: {runState.TurnCount}
+- toolCallCount: {runState.ToolCallCount}
+- directAnswerAttempts: {runState.DirectAnswerAttempts}
+- routedModel: {runState.RoutedModel ?? runState.ConfiguredModel}
+- routedProvider: {runState.RoutedProvider ?? "unknown"}
+
+Outstanding verification
+{obligations}
+
+Recent evidence
+{evidence}
+
+Guidance highlights
+{bestPractices}
+""";
+    }
+}