Add validation to LoadFromXml method for consistency with LoadFromStream

Co-authored-by: jongalloway <[email protected]>

Author: Copilot

src/NLWebNet/Services/ToolDefinitionLoader.cs

@@ -101,9 +101,20 @@ public ToolDefinitions LoadFromXml(string xmlContent)
             });
 
             var result = (ToolDefinitions?)_serializer.Deserialize(xmlReader);
-            return result ?? new ToolDefinitions();
+            var toolDefinitions = result ?? new ToolDefinitions();
+
+            // Validate the loaded definitions
+            var validationErrors = ValidateToolDefinitions(toolDefinitions).ToList();
+            if (validationErrors.Any())
+            {
+                var errorMessage = $"Tool definitions validation failed: {string.Join("; ", validationErrors)}";
+                _logger.LogError(errorMessage);
+                throw new InvalidOperationException(errorMessage);
+            }
+
+            return toolDefinitions;
         }
-        catch (Exception ex)
+        catch (Exception ex) when (!(ex is InvalidOperationException))
         {
             _logger.LogError(ex, "Failed to deserialize tool definitions from XML content");
             throw new InvalidOperationException("Failed to parse tool definitions XML", ex);

tests/NLWebNet.Tests/Extensions/ConfigurationFormatSupportTests.cs

@@ -112,6 +112,30 @@ public void XmlToolDefinitions_BasicLoading_ShouldWork()
         Assert.IsTrue(result.Tools[0].Enabled);
     }
 
+    [TestMethod]
+    public void XmlToolDefinitions_ValidationErrors_ShouldThrowException()
+    {
+        // Arrange - XML with validation errors (empty tool ID)
+        var xml = @"<?xml version=""1.0"" encoding=""utf-8""?>
+<ToolDefinitions>
+    <Tool id="""" name=""Invalid Tool"" type=""search"" enabled=""true"" priority=""1"">
+        <Description>Tool with empty ID</Description>
+        <Parameters>
+            <MaxResults>10</MaxResults>
+            <TimeoutSeconds>30</TimeoutSeconds>
+        </Parameters>
+    </Tool>
+</ToolDefinitions>";
+
+        var logger = Substitute.For<Microsoft.Extensions.Logging.ILogger<ToolDefinitionLoader>>();
+        var loader = new ToolDefinitionLoader(logger);
+
+        // Act & Assert
+        var exception = Assert.ThrowsException<InvalidOperationException>(() => loader.LoadFromXml(xml));
+        Assert.IsTrue(exception.Message.Contains("Tool definitions validation failed"));
+        Assert.IsTrue(exception.Message.Contains("Tool ID cannot be empty"));
+    }
+
     [TestMethod]
     public void ConfigurationExtensions_ServiceRegistration_ShouldWork()
     {