Fix MCP batch query failure reporting

changelog.d/unreleased/1472.fixed.md

@@ -0,0 +1,17 @@
+---
+category: fixed
+issues:
+  - 1472
+affected:
+  - src/CodeIndex/Mcp/McpToolHandlers.cs
+  - src/CodeIndex/Mcp/McpToolDefinitions.cs
+  - tests/CodeIndex.Tests/McpServerTests.cs
+---
+
+## English
+
+- **MCP `batch_query` now reports failure scope (#1472)** — batch responses include `failure_scope` with `none`, `isolated`, or `cascading`, plus `cascade_started_at_index` when truncation prevents later slots from running.
+
+## 日本語
+
+- **MCP `batch_query` が失敗スコープを返すようになりました (#1472)** — batch response に `failure_scope`（`none` / `isolated` / `cascading`）を追加し、truncation により後続スロットを実行できない場合は `cascade_started_at_index` も返します。

changelog.d/unreleased/1615.fixed.md

@@ -0,0 +1,16 @@
+---
+category: fixed
+issues:
+  - 1615
+affected:
+  - src/CodeIndex/Mcp/McpToolHandlers.cs
+  - tests/CodeIndex.Tests/McpServerTests.cs
+---
+
+## English
+
+- **MCP `batch_query` now rejects type-mismatched inner arguments (#1615)** — batched tool slots validate argument JSON types before dispatch, so values such as `"limit": "twenty"` produce a slot error instead of silently using defaults.
+
+## 日本語
+
+- **MCP `batch_query` が内側引数の型不一致を拒否するようになりました (#1615)** — batched tool slot は dispatch 前に argument JSON の型を検証するため、`"limit": "twenty"` のような値は既定値に戻らず slot error になります。

changelog.d/unreleased/1616.fixed.md

@@ -0,0 +1,17 @@
+---
+category: fixed
+issues:
+  - 1616
+affected:
+  - src/CodeIndex/Mcp/McpToolHandlers.cs
+  - src/CodeIndex/Mcp/McpToolDefinitions.cs
+  - tests/CodeIndex.Tests/McpServerTests.cs
+---
+
+## English
+
+- **MCP `batch_query` now exposes top-level partial-failure counts (#1616)** — batch responses include `total_count`, `success_count`, `failure_count`, and `partial_failure` at the top level so clients can detect aggregate failures without scanning every slot.
+
+## 日本語
+
+- **MCP `batch_query` が top-level の部分失敗件数を返すようになりました (#1616)** — batch response に top-level の `total_count`、`success_count`、`failure_count`、`partial_failure` を追加し、クライアントが全 slot を走査せず集計失敗を検出できるようにしました。

src/CodeIndex/Mcp/McpToolDefinitions.cs

@@ -377,7 +377,7 @@ private JsonNode HandleToolsList(JsonNode? id)
                 ReadOnlyAnnotations()),
             CreateToolDefinition(
                 "batch_query",
-                "Execute multiple read-only queries in a single call and return all results. Dramatically reduces round-trips for AI agents. / 複数の読み取り専用クエリを1回の呼び出しで実行し、全結果を返す。AIエージェントの往復回数を劇的に削減。",
+                "Execute multiple read-only queries in a single call and return all results plus top-level success/failure counts, partial_failure, and failure_scope (none/isolated/cascading). Dramatically reduces round-trips for AI agents. / 複数の読み取り専用クエリを1回の呼び出しで実行し、全結果に加えてトップレベルの成功/失敗件数、partial_failure、failure_scope（none/isolated/cascading）を返す。AIエージェントの往復回数を劇的に削減。",
                 new JsonObject
                 {
                     ["type"] = "object",

src/CodeIndex/Mcp/McpToolHandlers.cs

@@ -384,6 +384,7 @@ private static List<string> ReadStringList(JsonNode? args, string propertyName)
                     ["unknown_argument"] = property.Key,
                 };
             }
+
         }
 
         if (ValidateToolArgumentTypes(toolName, obj) is JsonObject typeError)
@@ -416,7 +417,7 @@ private static List<string> ReadStringList(JsonNode? args, string propertyName)
 
     private static bool TryGetExpectedJsonType(string toolName, string argumentName, out string expected)
     {
-        if (argumentName is "path" or "project" or "excludePaths" or "names")
+        if (argumentName is "path" or "project" or "excludePaths" or "names" or "files" or "commits" or "changedBetween")
         {
             expected = string.Empty;
             return false;
@@ -426,7 +427,7 @@ private static bool TryGetExpectedJsonType(string toolName, string argumentName,
         {
             "limit" or "offset" or "snippetLines" or "maxLineWidth" or "before" or "after" or
                 "focusLine" or "focusColumn" or "focusLength" or "startLine" or "endLine" or
-                "maxHops" or "maxDepth" or "depth" or "parallelism" => "integer",
+                "maxHops" or "maxDepth" or "depth" or "parallelism" or "maxFileBytes" => "integer",
             "excludeTests" or "includeGenerated" or "rawQuery" or "noDedup" or "exactSubstring" or
                 "exactName" or "exact" or "prefix" or "countOnly" or "includeBody" or "lsp_compatible" or
                 "regex" or "withPaths" or "rebuild" or "dryRun" or "dry_run" or "force" or "optimize" => "boolean",
@@ -2145,9 +2146,11 @@ private JsonNode ExecuteBatchQuery(JsonNode? id, JsonNode? args)
         var totalStopwatch = Stopwatch.StartNew();
         int successCount = 0;
         int failureCount = 0;
+        int? cascadeStartedAtIndex = null;
         var truncated = false;
         var responseByteLimit = GetBatchQueryResponseByteLimit();
         var estimatedResponseBytes = EstimateBatchResponseBytes(id, "Executed 0 queries.", queries.Count, successCount, failureCount,
+            GetBatchFailureScope(queries.Count, successCount, failureCount, cascadeStartedAtIndex), cascadeStartedAtIndex,
             responseByteLimit, resultsArray, truncated: false, truncatedQueries);
 
         bool TryAppendResult(JsonObject entry, string? toolName, JsonNode? toolArgs, int requestIndex, bool successfulSlot = false, bool failedSlot = false)
@@ -2161,10 +2164,12 @@ bool TryAppendResult(JsonObject entry, string? toolName, JsonNode? toolArgs, int
                 ? $"Executed {candidateExecutedCount} of {queries.Count} queries in 0 ms (all succeeded)."
                 : $"Executed {candidateExecutedCount} of {queries.Count} queries in 0 ms ({candidateSuccessCount} succeeded, {candidateFailureCount} failed).";
             var candidateBytes = EstimateBatchResponseBytes(id, candidateSummary, queries.Count, candidateSuccessCount, candidateFailureCount,
+                GetBatchFailureScope(queries.Count, candidateSuccessCount, candidateFailureCount, cascadeStartedAtIndex), cascadeStartedAtIndex,
                 responseByteLimit, candidateResults, truncated: false, truncatedQueries);
             if (candidateBytes > responseByteLimit)
             {
                 truncated = true;
+                cascadeStartedAtIndex ??= requestIndex;
                 truncatedQueries.Add(new JsonObject
                 {
                     ["request_index"] = requestIndex,
@@ -2264,6 +2269,7 @@ void AppendRateLimitedSlot(int requestIndex, string? toolName, JsonNode? toolArg
             if (truncated)
             {
                 slotStopwatch.Stop();
+                cascadeStartedAtIndex ??= requestIndex;
                 truncatedQueries.Add(new JsonObject
                 {
                     ["request_index"] = requestIndex,
@@ -2467,6 +2473,12 @@ void AppendRateLimitedSlot(int requestIndex, string? toolName, JsonNode? toolArg
         JsonObject BuildPayload() => new()
         {
             ["count"] = resultsArray.Count,
+            ["total_count"] = queries.Count,
+            ["success_count"] = successCount,
+            ["failure_count"] = failureCount,
+            ["partial_failure"] = failureCount > 0 || cascadeStartedAtIndex.HasValue,
+            ["failure_scope"] = GetBatchFailureScope(queries.Count, successCount, failureCount, cascadeStartedAtIndex),
+            ["cascade_started_at_index"] = cascadeStartedAtIndex,
             ["metadata"] = new JsonObject
             {
                 ["submitted"] = queries.Count,
@@ -2543,11 +2555,17 @@ private int EstimateJsonUtf8Bytes(JsonNode node) =>
         Encoding.UTF8.GetByteCount(node.ToJsonString(_jsonOptions));
 
     private int EstimateBatchResponseBytes(JsonNode? id, string summary, int submittedCount, int successCount, int failureCount,
-        int responseByteLimit, JsonArray resultsArray, bool truncated, JsonArray truncatedQueries)
+        string failureScope, int? cascadeStartedAtIndex, int responseByteLimit, JsonArray resultsArray, bool truncated, JsonArray truncatedQueries)
     {
         var payload = new JsonObject
         {
             ["count"] = resultsArray.Count,
+            ["total_count"] = submittedCount,
+            ["success_count"] = successCount,
+            ["failure_count"] = failureCount,
+            ["partial_failure"] = failureCount > 0 || cascadeStartedAtIndex.HasValue,
+            ["failure_scope"] = failureScope,
+            ["cascade_started_at_index"] = cascadeStartedAtIndex,
             ["metadata"] = new JsonObject
             {
                 ["submitted"] = submittedCount,
@@ -2570,6 +2588,13 @@ private int EstimateBatchResponseBytes(JsonNode? id, string summary, int submitt
         return EstimateJsonUtf8Bytes(CreateToolResult(id, summary, payload));
     }
 
+    private static string GetBatchFailureScope(int submittedCount, int successCount, int failureCount, int? cascadeStartedAtIndex)
+    {
+        if (cascadeStartedAtIndex.HasValue && cascadeStartedAtIndex.Value < submittedCount)
+            return "cascading";
+        return failureCount == 0 ? "none" : "isolated";
+    }
+
     private static JsonArray CloneJsonArray(JsonArray source)
     {
         var clone = new JsonArray();

tests/CodeIndex.Tests/McpServerTests.cs

@@ -6381,6 +6381,12 @@ public void ToolsCall_BatchQuery_ExecutesMultipleQueries()
         Assert.Equal(2, metadata["submitted"]!.GetValue<int>());
         Assert.Equal(2, metadata["executed"]!.GetValue<int>());
         Assert.Equal(0, metadata["errors"]!.GetValue<int>());
+        var structured = response["result"]!["structuredContent"]!;
+        Assert.Equal(2, structured["total_count"]!.GetValue<int>());
+        Assert.Equal(2, structured["success_count"]!.GetValue<int>());
+        Assert.Equal(0, structured["failure_count"]!.GetValue<int>());
+        Assert.False(structured["partial_failure"]!.GetValue<bool>());
+        Assert.Equal("none", structured["failure_scope"]!.GetValue<string>());
     }
 
     [Fact]
@@ -6458,6 +6464,11 @@ public void ToolsCall_BatchQuery_CountsFailuresInEnvelope_Issue1537()
         Assert.Equal(3, metadata["submitted"]!.GetValue<int>());
         Assert.Equal(3, metadata["executed"]!.GetValue<int>());
         Assert.Equal(2, metadata["errors"]!.GetValue<int>());
+        Assert.Equal(3, structured["total_count"]!.GetValue<int>());
+        Assert.Equal(1, structured["success_count"]!.GetValue<int>());
+        Assert.Equal(2, structured["failure_count"]!.GetValue<int>());
+        Assert.True(structured["partial_failure"]!.GetValue<bool>());
+        Assert.Equal("isolated", structured["failure_scope"]!.GetValue<string>());
 
         var results = structured["results"]!.AsArray();
         Assert.Equal(3, results.Count);
@@ -6477,6 +6488,29 @@ public void ToolsCall_BatchQuery_CountsFailuresInEnvelope_Issue1537()
         Assert.Contains("1 succeeded, 2 failed", text);
     }
 
+    [Fact]
+    public void ToolsCall_BatchQuery_RejectsTypeMismatchedInnerArguments_Issue1615()
+    {
+        var request = JsonNode.Parse("""{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"batch_query","arguments":{"queries":[{"tool":"search","arguments":{"query":"App","limit":"twenty"}},{"tool":"search","arguments":{"query":"App","format":false}},{"tool":"ping"}]}}}""")!;
+        var response = _server.HandleMessage(request)!;
+
+        var structured = response["result"]!["structuredContent"]!;
+        Assert.Equal(3, structured["total_count"]!.GetValue<int>());
+        Assert.Equal(1, structured["success_count"]!.GetValue<int>());
+        Assert.Equal(2, structured["failure_count"]!.GetValue<int>());
+        Assert.True(structured["partial_failure"]!.GetValue<bool>());
+        Assert.Equal("isolated", structured["failure_scope"]!.GetValue<string>());
+
+        var results = structured["results"]!.AsArray();
+        Assert.Equal(3, results.Count);
+        Assert.False(results[0]!["ok"]!.GetValue<bool>());
+        Assert.Contains("Invalid type for argument 'limit'", results[0]!["error"]!.GetValue<string>());
+        Assert.Equal(McpErrorEnvelope.CategoryInvalidArgument, results[0]!["category"]!.GetValue<string>());
+        Assert.False(results[1]!["ok"]!.GetValue<bool>());
+        Assert.Contains("Invalid type for argument 'format'", results[1]!["error"]!.GetValue<string>());
+        Assert.True(results[2]!["ok"]!.GetValue<bool>());
+    }
+
     [Fact]
     public void ToolsCall_BatchQuery_ReportsMalformedSlotsAndActualExecutionCounts_Issue1838_1992_1994()
     {
@@ -6557,6 +6591,9 @@ public void ToolsCall_BatchQuery_TruncatesAggregateResponse_Issue1416()
             Assert.Equal(2, structured["metadata"]!["submitted"]!.GetValue<int>());
             Assert.Equal(2, structured["metadata"]!["executed"]!.GetValue<int>());
             Assert.Equal(0, structured["metadata"]!["errors"]!.GetValue<int>());
+            Assert.Equal("cascading", structured["failure_scope"]!.GetValue<string>());
+            Assert.NotNull(structured["cascade_started_at_index"]);
+            Assert.True(structured["partial_failure"]!.GetValue<bool>());
 
             var truncatedQueries = structured["truncated_queries"]!.AsArray();
             Assert.NotEmpty(truncatedQueries);