.Net: Expose any custom attributes on the underlying function method

dotnet/samples/Concepts/FunctionCalling/NexusRaven_FunctionCalling.cs

@@ -127,6 +127,7 @@ private static KernelPlugin ImportFunctions(Kernel kernel)
                 (string cityName) => "12°C\nWind: 11 KMPH\nHumidity: 48%\nMostly cloudy",
                 "GetWeatherForCity",
                 "Gets the current weather for the specified city",
+                [],
                 new List<KernelParameterMetadata>
                 {
                     new("cityName") { Description = "The city name", ParameterType = string.Empty.GetType() }

dotnet/src/Connectors/Connectors.Google.UnitTests/GeminiToolCallBehaviorTests.cs

@@ -200,6 +200,7 @@ private static KernelPlugin GetTestPlugin()
             (string parameter1, string parameter2) => "Result1",
             "MyFunction",
             "Test Function",
+            [],
             [new KernelParameterMetadata("parameter1"), new KernelParameterMetadata("parameter2")],
             new KernelReturnParameterMetadata { ParameterType = typeof(string), Description = "Function Result" });
 

dotnet/src/Connectors/Connectors.UnitTests/OpenAI/ToolCallBehaviorTests.cs

@@ -228,6 +228,7 @@ private KernelPlugin GetTestPlugin()
             (string parameter1, string parameter2) => "Result1",
             "MyFunction",
             "Test Function",
+            [],
             [new KernelParameterMetadata("parameter1"), new KernelParameterMetadata("parameter2")],
             new KernelReturnParameterMetadata { ParameterType = typeof(string), Description = "Function Result" });
 

dotnet/src/Experimental/Agents.UnitTests/Extensions/KernelFunctionExtensionTests.cs

@@ -1,5 +1,6 @@
 // Copyright (c) Microsoft. All rights reserved.
 
+using System;
 using System.Collections.Generic;
 using Microsoft.SemanticKernel;
 using Microsoft.SemanticKernel.Experimental.Agents;
@@ -33,8 +34,9 @@ public static void GetToolModelFromFunction()
 
         var requiredParam = new KernelParameterMetadata("required") { IsRequired = true };
         var optionalParam = new KernelParameterMetadata("optional");
+        var attributes = new List<Attribute>();
         var parameters = new List<KernelParameterMetadata> { requiredParam, optionalParam };
-        var function = KernelFunctionFactory.CreateFromMethod(() => true, ToolName, FunctionDescription, parameters);
+        var function = KernelFunctionFactory.CreateFromMethod(() => true, ToolName, FunctionDescription, attributes, parameters);
 
         var toolModel = function.ToToolModel(PluginName);
         var properties = toolModel.Function?.Parameters.Properties;

dotnet/src/SemanticKernel.Abstractions/Functions/KernelFunction.cs

@@ -96,14 +96,15 @@ public abstract class KernelFunction
     /// </summary>
     /// <param name="name">A name of the function to use as its <see cref="KernelFunction.Name"/>.</param>
     /// <param name="description">The description of the function to use as its <see cref="KernelFunction.Description"/>.</param>
+    /// <param name="attributes">The attributes on the function.</param>
     /// <param name="parameters">The metadata describing the parameters to the function.</param>
     /// <param name="returnParameter">The metadata describing the return parameter of the function.</param>
     /// <param name="executionSettings">
     /// The <see cref="PromptExecutionSettings"/> to use with the function. These will apply unless they've been
     /// overridden by settings passed into the invocation of the function.
     /// </param>
-    internal KernelFunction(string name, string description, IReadOnlyList<KernelParameterMetadata> parameters, KernelReturnParameterMetadata? returnParameter = null, Dictionary<string, PromptExecutionSettings>? executionSettings = null)
-        : this(name, null, description, parameters, returnParameter, executionSettings)
+    internal KernelFunction(string name, string description, IReadOnlyList<Attribute> attributes, IReadOnlyList<KernelParameterMetadata> parameters, KernelReturnParameterMetadata? returnParameter = null, Dictionary<string, PromptExecutionSettings>? executionSettings = null)
+        : this(name, null, description, attributes, parameters, returnParameter, executionSettings)
     {
     }
 
@@ -113,14 +114,15 @@ internal KernelFunction(string name, string description, IReadOnlyList<KernelPar
     /// <param name="name">A name of the function to use as its <see cref="KernelFunction.Name"/>.</param>
     /// <param name="pluginName">The name of the plugin this function instance has been added to.</param>
     /// <param name="description">The description of the function to use as its <see cref="KernelFunction.Description"/>.</param>
+    /// <param name="attributes">The attributes on the function.</param>
     /// <param name="parameters">The metadata describing the parameters to the function.</param>
     /// <param name="returnParameter">The metadata describing the return parameter of the function.</param>
     /// <param name="executionSettings">
     /// The <see cref="PromptExecutionSettings"/> to use with the function. These will apply unless they've been
     /// overridden by settings passed into the invocation of the function.
     /// </param>
     /// <param name="additionalMetadata">Properties/metadata associated with the function itself rather than its parameters and return type.</param>
-    internal KernelFunction(string name, string? pluginName, string description, IReadOnlyList<KernelParameterMetadata> parameters, KernelReturnParameterMetadata? returnParameter = null, Dictionary<string, PromptExecutionSettings>? executionSettings = null, ReadOnlyDictionary<string, object?>? additionalMetadata = null)
+    internal KernelFunction(string name, string? pluginName, string description, IReadOnlyList<Attribute> attributes, IReadOnlyList<KernelParameterMetadata> parameters, KernelReturnParameterMetadata? returnParameter = null, Dictionary<string, PromptExecutionSettings>? executionSettings = null, ReadOnlyDictionary<string, object?>? additionalMetadata = null)
     {
         Verify.NotNull(name);
         Verify.ParametersUniqueness(parameters);
@@ -129,6 +131,7 @@ internal KernelFunction(string name, string? pluginName, string description, IRe
         {
             PluginName = pluginName,
             Description = description,
+            Attributes = attributes,
             Parameters = parameters,
             ReturnParameter = returnParameter ?? KernelReturnParameterMetadata.Empty,
             AdditionalProperties = additionalMetadata ?? KernelFunctionMetadata.s_emptyDictionary,

dotnet/src/SemanticKernel.Abstractions/Functions/KernelFunctionMetadata.cs

@@ -16,6 +16,8 @@ public sealed class KernelFunctionMetadata
     private string _name = string.Empty;
     /// <summary>The description of the function.</summary>
     private string _description = string.Empty;
+    /// <summary>The function's attributes.</summary>
+    private IReadOnlyList<Attribute> _attributes = [];
     /// <summary>The function's parameters.</summary>
     private IReadOnlyList<KernelParameterMetadata> _parameters = [];
     /// <summary>The function's return parameter.</summary>
@@ -46,6 +48,7 @@ public KernelFunctionMetadata(KernelFunctionMetadata metadata)
         this.Name = metadata.Name;
         this.PluginName = metadata.PluginName;
         this.Description = metadata.Description;
+        this.Attributes = metadata.Attributes;
         this.Parameters = metadata.Parameters;
         this.ReturnParameter = metadata.ReturnParameter;
         this.AdditionalProperties = metadata.AdditionalProperties;
@@ -74,6 +77,18 @@ public string Description
         init => this._description = value ?? string.Empty;
     }
 
+    /// <summary>Gets the attributes on the function.</summary>
+    /// <remarks>If the function has no attributes, the returned list will be empty.</remarks>
+    public IReadOnlyList<Attribute> Attributes
+    {
+        get => this._attributes;
+        init
+        {
+            Verify.NotNull(value);
+            this._attributes = value;
+        }
+    }
+
     /// <summary>Gets the metadata for the parameters to the function.</summary>
     /// <remarks>If the function has no parameters, the returned list will be empty.</remarks>
     public IReadOnlyList<KernelParameterMetadata> Parameters

dotnet/src/SemanticKernel.Core/Functions/KernelFunctionFactory.cs

@@ -23,6 +23,7 @@ public static class KernelFunctionFactory
     /// <param name="method">The method to be represented via the created <see cref="KernelFunction"/>.</param>
     /// <param name="functionName">The name to use for the function. If null, it will default to one derived from the method represented by <paramref name="method"/>.</param>
     /// <param name="description">The description to use for the function. If null, it will default to one derived from the method represented by <paramref name="method"/>, if possible (e.g. via a <see cref="DescriptionAttribute"/> on the method).</param>
+    /// <param name="attributes">Optional function attributes. If null, it will default to those derived from the method represented by <paramref name="method"/>.</param>
     /// <param name="parameters">Optional parameter descriptions. If null, it will default to one derived from the method represented by <paramref name="method"/>.</param>
     /// <param name="returnParameter">Optional return parameter description. If null, it will default to one derived from the method represented by <paramref name="method"/>.</param>
     /// <param name="loggerFactory">The <see cref="ILoggerFactory"/> to use for logging. If null, no logging will be performed.</param>
@@ -31,10 +32,11 @@ public static KernelFunction CreateFromMethod(
         Delegate method,
         string? functionName = null,
         string? description = null,
+        IEnumerable<Attribute>? attributes = null,
         IEnumerable<KernelParameterMetadata>? parameters = null,
         KernelReturnParameterMetadata? returnParameter = null,
         ILoggerFactory? loggerFactory = null) =>
-        CreateFromMethod(method.Method, method.Target, functionName, description, parameters, returnParameter, loggerFactory);
+        CreateFromMethod(method.Method, method.Target, functionName, description, attributes, parameters, returnParameter, loggerFactory);
 
     /// <summary>
     /// Creates a <see cref="KernelFunction"/> instance for a method, specified via a delegate.
@@ -55,6 +57,7 @@ public static KernelFunction CreateFromMethod(
     /// <param name="target">The target object for the <paramref name="method"/> if it represents an instance method. This should be null if and only if <paramref name="method"/> is a static method.</param>
     /// <param name="functionName">The name to use for the function. If null, it will default to one derived from the method represented by <paramref name="method"/>.</param>
     /// <param name="description">The description to use for the function. If null, it will default to one derived from the method represented by <paramref name="method"/>, if possible (e.g. via a <see cref="DescriptionAttribute"/> on the method).</param>
+    /// <param name="attributes">Optional function attributes. If null, it will default to those derived from the method represented by <paramref name="method"/>.</param>
     /// <param name="parameters">Optional parameter descriptions. If null, it will default to ones derived from the method represented by <paramref name="method"/>.</param>
     /// <param name="returnParameter">Optional return parameter description. If null, it will default to one derived from the method represented by <paramref name="method"/>.</param>
     /// <param name="loggerFactory">The <see cref="ILoggerFactory"/> to use for logging. If null, no logging will be performed.</param>
@@ -64,10 +67,11 @@ public static KernelFunction CreateFromMethod(
         object? target = null,
         string? functionName = null,
         string? description = null,
+        IEnumerable<Attribute>? attributes = null,
         IEnumerable<KernelParameterMetadata>? parameters = null,
         KernelReturnParameterMetadata? returnParameter = null,
         ILoggerFactory? loggerFactory = null) =>
-        KernelFunctionFromMethod.Create(method, target, functionName, description, parameters, returnParameter, loggerFactory);
+        KernelFunctionFromMethod.Create(method, target, functionName, description, attributes, parameters, returnParameter, loggerFactory);
 
     /// <summary>
     /// Creates a <see cref="KernelFunction"/> instance for a method, specified via an <see cref="MethodInfo"/> instance

dotnet/src/SemanticKernel.Core/Functions/KernelFunctionFromMethod.cs

@@ -37,6 +37,7 @@ internal sealed partial class KernelFunctionFromMethod : KernelFunction
     /// <param name="target">The target object for the <paramref name="method"/> if it represents an instance method. This should be null if and only if <paramref name="method"/> is a static method.</param>
     /// <param name="functionName">The name to use for the function. If null, it will default to one derived from the method represented by <paramref name="method"/>.</param>
     /// <param name="description">The description to use for the function. If null, it will default to one derived from the method represented by <paramref name="method"/>, if possible (e.g. via a <see cref="DescriptionAttribute"/> on the method).</param>
+    /// <param name="attributes">Optional function attributes. If null, it will default to those derived from the method represented by <paramref name="method"/>.</param>
     /// <param name="parameters">Optional parameter descriptions. If null, it will default to one derived from the method represented by <paramref name="method"/>.</param>
     /// <param name="returnParameter">Optional return parameter description. If null, it will default to one derived from the method represented by <paramref name="method"/>.</param>
     /// <param name="loggerFactory">The <see cref="ILoggerFactory"/> to use for logging. If null, no logging will be performed.</param>
@@ -46,6 +47,7 @@ public static KernelFunction Create(
         object? target = null,
         string? functionName = null,
         string? description = null,
+        IEnumerable<Attribute>? attributes = null,
         IEnumerable<KernelParameterMetadata>? parameters = null,
         KernelReturnParameterMetadata? returnParameter = null,
         ILoggerFactory? loggerFactory = null)
@@ -57,6 +59,7 @@ public static KernelFunction Create(
             {
                 FunctionName = functionName,
                 Description = description,
+                Attributes = attributes,
                 Parameters = parameters,
                 ReturnParameter = returnParameter,
                 LoggerFactory = loggerFactory
@@ -87,6 +90,7 @@ public static KernelFunction Create(
             methodDetails.Function,
             methodDetails.Name,
             options?.Description ?? methodDetails.Description,
+            options?.Attributes?.ToList() ?? methodDetails.Attributes,
             options?.Parameters?.ToList() ?? methodDetails.Parameters,
             options?.ReturnParameter ?? methodDetails.ReturnParameter,
             options?.AdditionalMetadata);
@@ -160,6 +164,7 @@ public override KernelFunction Clone(string pluginName)
             this.Name,
             pluginName,
             this.Description,
+            this.Metadata.Attributes,
             this.Metadata.Parameters,
             this.Metadata.ReturnParameter,
             this.Metadata.AdditionalProperties);
@@ -175,16 +180,17 @@ private delegate ValueTask<FunctionResult> ImplementationFunc(
     private static readonly object[] s_cancellationTokenNoneArray = [CancellationToken.None];
     private readonly ImplementationFunc _function;
 
-    private record struct MethodDetails(string Name, string Description, ImplementationFunc Function, List<KernelParameterMetadata> Parameters, KernelReturnParameterMetadata ReturnParameter);
+    private record struct MethodDetails(string Name, string Description, ImplementationFunc Function, List<Attribute> Attributes, List<KernelParameterMetadata> Parameters, KernelReturnParameterMetadata ReturnParameter);
 
     private KernelFunctionFromMethod(
         ImplementationFunc implementationFunc,
         string functionName,
         string description,
+        IReadOnlyList<Attribute> attributes,
         IReadOnlyList<KernelParameterMetadata> parameters,
         KernelReturnParameterMetadata returnParameter,
         ReadOnlyDictionary<string, object?>? additionalMetadata = null) :
-        this(implementationFunc, functionName, null, description, parameters, returnParameter, additionalMetadata)
+        this(implementationFunc, functionName, null, description, attributes, parameters, returnParameter, additionalMetadata)
     {
     }
 
@@ -193,10 +199,11 @@ private KernelFunctionFromMethod(
         string functionName,
         string? pluginName,
         string description,
+        IReadOnlyList<Attribute> attributes,
         IReadOnlyList<KernelParameterMetadata> parameters,
         KernelReturnParameterMetadata returnParameter,
         ReadOnlyDictionary<string, object?>? additionalMetadata = null) :
-        base(functionName, pluginName, description, parameters, returnParameter, additionalMetadata: additionalMetadata)
+        base(functionName, pluginName, description, attributes, parameters, returnParameter, additionalMetadata: additionalMetadata)
     {
         Verify.ValidFunctionName(functionName);
 
@@ -281,6 +288,7 @@ ValueTask<FunctionResult> Function(Kernel kernel, KernelFunction function, Kerne
             Function = Function,
             Name = functionName!,
             Description = method.GetCustomAttribute<DescriptionAttribute>(inherit: true)?.Description ?? "",
+            Attributes = [.. Attribute.GetCustomAttributes(method, inherit: true)],
             Parameters = argParameterViews,
             ReturnParameter = new KernelReturnParameterMetadata()
             {
@@ -470,7 +478,7 @@ private static bool TryToDeserializeValue(object value, Type targetType, out obj
                 JsonDocument document => document.Deserialize(targetType),
                 JsonNode node => node.Deserialize(targetType),
                 JsonElement element => element.Deserialize(targetType),
-                // The JSON can be represented by other data types from various libraries. For example, JObject, JToken, and JValue from the Newtonsoft.Json library.  
+                // The JSON can be represented by other data types from various libraries. For example, JObject, JToken, and JValue from the Newtonsoft.Json library.
                 // Since we don't take dependencies on these libraries and don't have access to the types here,
                 // the only way to deserialize those types is to convert them to a string first by calling the 'ToString' method.
                 // Attempting to use the 'JsonSerializer.Serialize' method, instead of calling the 'ToString' directly on those types, can lead to unpredictable outcomes.
@@ -739,7 +747,7 @@ private static void ThrowForInvalidSignatureIf([DoesNotReturnIf(true)] bool cond
                     {
                         if (input?.GetType() is Type type && converter.CanConvertFrom(type))
                         {
-                            // This line performs string to type conversion 
+                            // This line performs string to type conversion
                             return converter.ConvertFrom(context: null, culture, input);
                         }
 

dotnet/src/SemanticKernel.Core/Functions/KernelFunctionFromMethodOptions.cs

@@ -25,6 +25,11 @@ public sealed class KernelFunctionFromMethodOptions
     /// </summary>
     public string? Description { get; init; }
 
+    /// <summary>
+    /// Optional function attributes. If null, it will default to what is derived from the passed <see cref="Delegate"/> or <see cref="MethodInfo"/>.
+    /// </summary>
+    public IEnumerable<Attribute>? Attributes { get; init; }
+
     /// <summary>
     /// Optional parameter descriptions. If null, it will default to one derived from the passed <see cref="Delegate"/> or <see cref="MethodInfo"/>.
     /// </summary>

dotnet/src/SemanticKernel.Core/Functions/KernelFunctionFromPrompt.cs

@@ -252,6 +252,7 @@ private KernelFunctionFromPrompt(
             functionName ?? CreateRandomFunctionName(),
             pluginName,
             description ?? string.Empty,
+            attributes: [],
             parameters,
             returnParameter,
             executionSettings)