Fix whitespace handling in MCP read_records select lists

src/Azure.DataApiBuilder.Mcp/BuiltInTools/ReadRecordsTool.cs

@@ -201,7 +201,7 @@ public async Task<CallToolResult> ExecuteAsync(
                 if (!string.IsNullOrWhiteSpace(select))
                 {
                     // Update the context to specify which fields will be returned from the entity.
-                    IEnumerable<string> fieldsReturnedForFind = select.Split(",").ToList();
+                    IEnumerable<string> fieldsReturnedForFind = select.Split(',').Select(field => field.Trim()).ToList();
                     context.UpdateReturnFields(fieldsReturnedForFind);
                 }
 

src/Service.Tests/Mcp/ReadRecordsToolMsSqlIntegrationTests.cs

@@ -61,6 +61,23 @@ public async Task ReadRecords_WithSelect_ReturnsSelectedFields()
             Assert.IsTrue(firstRecord.TryGetProperty("title", out _), "Expected 'title' field in result.");
         }
 
+        /// <summary>
+        /// Reads records with whitespace after a comma in the select clause.
+        /// </summary>
+        [TestMethod]
+        public async Task ReadRecords_WithWhitespaceAfterSelectComma_ReturnsSelectedFields()
+        {
+            CallToolResult result = await ExecuteReadAsync("Book", select: "id, title");
+
+            AssertSuccess(result, "ReadRecords with whitespace after a select comma should succeed.");
+
+            JsonElement root = ParseResultRoot(result);
+            JsonElement records = GetRecordsArray(root);
+            JsonElement firstRecord = records[0];
+            Assert.IsTrue(firstRecord.TryGetProperty("id", out _), "Expected 'id' field in result.");
+            Assert.IsTrue(firstRecord.TryGetProperty("title", out _), "Expected 'title' field in result.");
+        }
+
         /// <summary>
         /// Reads records with an OData filter expression and verifies filtered results are returned.
         /// </summary>