Simplify MethodInfo resolution to use function.UnderlyingMethod directly

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

Author: Copilot

src/ModelContextProtocol.Core/Server/AIFunctionMcpServerPrompt.cs

@@ -140,10 +140,9 @@ private static AIFunctionFactoryOptions CreateAIFunctionFactoryOptions(
         };
 
         // Populate Meta from options and/or McpMetaAttribute instances if a MethodInfo is available
-        MethodInfo? method = options?.Metadata?.FirstOrDefault(m => m is MethodInfo) as MethodInfo ?? function.UnderlyingMethod;
-        if (method is not null)
+        if (function.UnderlyingMethod is not null)
         {
-            prompt.Meta = AIFunctionMcpServerTool.CreateMetaFromAttributes(method, options?.Meta, options?.SerializerOptions);
+            prompt.Meta = AIFunctionMcpServerTool.CreateMetaFromAttributes(function.UnderlyingMethod, options?.Meta, options?.SerializerOptions);
         }
         else if (options?.Meta is not null)
         {

src/ModelContextProtocol.Core/Server/AIFunctionMcpServerResource.cs

@@ -213,11 +213,10 @@ private static AIFunctionFactoryOptions CreateAIFunctionFactoryOptions(
         string name = options?.Name ?? function.Name;
 
         // Populate Meta from options and/or McpMetaAttribute instances if a MethodInfo is available
-        MethodInfo? method = options?.Metadata?.FirstOrDefault(m => m is MethodInfo) as MethodInfo ?? function.UnderlyingMethod;
         JsonObject? meta = null;
-        if (method is not null)
+        if (function.UnderlyingMethod is not null)
         {
-            meta = AIFunctionMcpServerTool.CreateMetaFromAttributes(method, options?.Meta, options?.SerializerOptions);
+            meta = AIFunctionMcpServerTool.CreateMetaFromAttributes(function.UnderlyingMethod, options?.Meta, options?.SerializerOptions);
         }
         else if (options?.Meta is not null)
         {

src/ModelContextProtocol.Core/Server/AIFunctionMcpServerTool.cs

@@ -145,10 +145,9 @@ options.OpenWorld is not null ||
             }
 
             // Populate Meta from options and/or McpMetaAttribute instances if a MethodInfo is available
-            MethodInfo? method = options.Metadata?.FirstOrDefault(m => m is MethodInfo) as MethodInfo ?? function.UnderlyingMethod;
-            if (method is not null)
+            if (function.UnderlyingMethod is not null)
             {
-                tool.Meta = CreateMetaFromAttributes(method, options.Meta, options.SerializerOptions);
+                tool.Meta = CreateMetaFromAttributes(function.UnderlyingMethod, options.Meta, options.SerializerOptions);
             }
             else if (options.Meta is not null)
             {