diff --git a/src/ModelContextProtocol/Server/AIFunctionMcpServerTool.cs b/src/ModelContextProtocol/Server/AIFunctionMcpServerTool.cs
index 562a8476c..6b0cf34b2 100644
--- a/src/ModelContextProtocol/Server/AIFunctionMcpServerTool.cs
+++ b/src/ModelContextProtocol/Server/AIFunctionMcpServerTool.cs
@@ -162,7 +162,7 @@ private static AIFunctionFactoryOptions CreateAIFunctionFactoryOptions(
         {
             Name = options?.Name ?? function.Name,
             Description = options?.Description ?? function.Description,
-            InputSchema = function.JsonSchema,     
+            InputSchema = FilterJsonSchema(function.JsonSchema),
         };
 
         if (options is not null)
@@ -220,6 +220,45 @@ options.OpenWorld is not null ||
         return newOptions;
     }
 
+    /// <summary>
+    /// Filters a JsonElement containing a schema to only include allowed properties: "type", "properties", and "required".
+    /// </summary>
+    private static JsonElement FilterJsonSchema(JsonElement schema)
+    {
+        using var memoryStream = new MemoryStream();
+        using var writer = new Utf8JsonWriter(memoryStream);
+
+        writer.WriteStartObject();
+
+        // Include "type" property if it exists
+        if (schema.TryGetProperty("type", out var typeElement))
+        {
+            writer.WritePropertyName("type");
+            typeElement.WriteTo(writer);
+        }
+
+        // Include "properties" property if it exists
+        if (schema.TryGetProperty("properties", out var propertiesElement))
+        {
+            writer.WritePropertyName("properties");
+            propertiesElement.WriteTo(writer);
+        }
+
+        // Include "required" property if it exists
+        if (schema.TryGetProperty("required", out var requiredElement))
+        {
+            writer.WritePropertyName("required");
+            requiredElement.WriteTo(writer);
+        }
+
+        writer.WriteEndObject();
+        writer.Flush();
+
+        memoryStream.Position = 0;
+        using var document = JsonDocument.Parse(memoryStream.ToArray());
+        return document.RootElement.Clone();
+    }
+
     /// <summary>Gets the <see cref="AIFunction"/> wrapped by this tool.</summary>
     internal AIFunction AIFunction { get; }
 
diff --git a/src/ModelContextProtocol/Utils/Json/McpJsonUtilities.cs b/src/ModelContextProtocol/Utils/Json/McpJsonUtilities.cs
index b759ba975..b5b7ac066 100644
--- a/src/ModelContextProtocol/Utils/Json/McpJsonUtilities.cs
+++ b/src/ModelContextProtocol/Utils/Json/McpJsonUtilities.cs
@@ -68,8 +68,12 @@ internal static bool IsValidMcpToolSchema(JsonElement element)
                 {
                     return false;
                 }
-
-                return true; // No need to check other properties
+            }
+            else if (!(property.NameEquals("properties") || 
+                       property.NameEquals("required")))
+            {
+                // Only "type", "properties", and "required" are allowed.
+                return false;
             }
         }
 
diff --git a/tests/ModelContextProtocol.Tests/Protocol/ProtocolTypeTests.cs b/tests/ModelContextProtocol.Tests/Protocol/ProtocolTypeTests.cs
index 7821d2ae6..1ad709749 100644
--- a/tests/ModelContextProtocol.Tests/Protocol/ProtocolTypeTests.cs
+++ b/tests/ModelContextProtocol.Tests/Protocol/ProtocolTypeTests.cs
@@ -30,6 +30,7 @@ public static void ToolInputSchema_HasValidDefaultSchema()
     [InlineData("""{"type":"number"}""")]
     [InlineData("""{"type":"array"}""")]
     [InlineData("""{"type":["object"]}""")]
+    [InlineData("""{"type":"object", "title": "MyAwesomeTool", "description": "It's awesome!", "properties": {}, "required" : ["NotAParam"] }""")]
     public static void ToolInputSchema_RejectsInvalidSchemaDocuments(string invalidSchema)
     {
         using var document = JsonDocument.Parse(invalidSchema);
@@ -41,7 +42,7 @@ public static void ToolInputSchema_RejectsInvalidSchemaDocuments(string invalidS
     [Theory]
     [InlineData("""{"type":"object"}""")]
     [InlineData("""{"type":"object", "properties": {}, "required" : [] }""")]
-    [InlineData("""{"type":"object", "title": "MyAwesomeTool", "description": "It's awesome!", "properties": {}, "required" : ["NotAParam"] }""")]
+    [InlineData("""{"type":"object", "properties": {}, "required" : ["NotAParam"] }""")]
     public static void ToolInputSchema_AcceptsValidSchemaDocuments(string validSchema)
     {
         using var document = JsonDocument.Parse(validSchema);