.NET: Support reflection for discovery of resources and scripts in class-based skills

dotnet/samples/02-agents/AgentSkills/Agent_Step03_ClassBasedSkills/Agent_Step03_ClassBasedSkills.csproj

@@ -6,7 +6,7 @@
 
     <Nullable>enable</Nullable>
     <ImplicitUsings>enable</ImplicitUsings>
-    <NoWarn>$(NoWarn);MAAI001</NoWarn>
+    <NoWarn>$(NoWarn);MAAI001;IDE0051</NoWarn>
   </PropertyGroup>
 
   <ItemGroup>

dotnet/samples/02-agents/AgentSkills/Agent_Step03_ClassBasedSkills/Program.cs

@@ -1,8 +1,9 @@
 // Copyright (c) Microsoft. All rights reserved.
 
-// This sample demonstrates how to define Agent Skills as C# classes using AgentClassSkill.
-// Class-based skills bundle all components into a single class implementation.
+// This sample demonstrates how to define Agent Skills as C# classes using AgentClassSkill
+// with attributes for automatic script and resource discovery.
 
+using System.ComponentModel;
 using System.Text.Json;
 using Azure.AI.OpenAI;
 using Azure.Identity;
@@ -44,17 +45,16 @@
 Console.WriteLine($"Agent: {response.Text}");
 
 /// <summary>
-/// A unit-converter skill defined as a C# class.
+/// A unit-converter skill defined as a C# class using attributes for discovery.
 /// </summary>
 /// <remarks>
-/// Class-based skills bundle all components (name, description, body, resources, scripts)
-/// into a single class.
+/// Properties annotated with <see cref="AgentSkillResourceAttribute"/> are automatically
+/// discovered as skill resources, and methods annotated with <see cref="AgentSkillScriptAttribute"/>
+/// are automatically discovered as skill scripts. Alternatively,
+/// <see cref="AgentSkill.Resources"/> and <see cref="AgentSkill.Scripts"/> can be overridden.
 /// </remarks>
-internal sealed class UnitConverterSkill : AgentClassSkill
+internal sealed class UnitConverterSkill : AgentClassSkill<UnitConverterSkill>
 {
-    private IReadOnlyList<AgentSkillResource>? _resources;
-    private IReadOnlyList<AgentSkillScript>? _scripts;
-
     /// <inheritdoc/>
     public override AgentSkillFrontmatter Frontmatter { get; } = new(
         "unit-converter",
@@ -69,31 +69,40 @@ Use this skill when the user asks to convert between units.
         3. Present the result clearly with both units.
         """;
 
-    /// <inheritdoc/>
-    public override IReadOnlyList<AgentSkillResource>? Resources => this._resources ??=
-    [
-        CreateResource(
-            "conversion-table",
-            """
-            # Conversion Tables
-
-            Formula: **result = value × factor**
-
-            | From        | To          | Factor   |
-            |-------------|-------------|----------|
-            | miles       | kilometers  | 1.60934  |
-            | kilometers  | miles       | 0.621371 |
-            | pounds      | kilograms   | 0.453592 |
-            | kilograms   | pounds      | 2.20462  |
-            """),
-    ];
-
-    /// <inheritdoc/>
-    public override IReadOnlyList<AgentSkillScript>? Scripts => this._scripts ??=
-    [
-        CreateScript("convert", ConvertUnits),
-    ];
+    /// <summary>
+    /// Gets the <see cref="JsonSerializerOptions"/> used to marshal parameters and return values
+    /// for scripts and resources.
+    /// </summary>
+    /// <remarks>
+    /// This override is not necessary for this sample, but can be used to provide custom
+    /// serialization options, for example a source-generated <c>JsonTypeInfoResolver</c>
+    /// for Native AOT compatibility.
+    /// </remarks>
+    protected override JsonSerializerOptions? SerializerOptions => null;
+
+    /// <summary>
+    /// A conversion table resource providing multiplication factors.
+    /// </summary>
+    [AgentSkillResource("conversion-table")]
+    [Description("Lookup table of multiplication factors for common unit conversions.")]
+    public string ConversionTable => """
+        # Conversion Tables
+
+        Formula: **result = value × factor**
+
+        | From        | To          | Factor   |
+        |-------------|-------------|----------|
+        | miles       | kilometers  | 1.60934  |
+        | kilometers  | miles       | 0.621371 |
+        | pounds      | kilograms   | 0.453592 |
+        | kilograms   | pounds      | 2.20462  |
+        """;
 
+    /// <summary>
+    /// Converts a value by the given factor.
+    /// </summary>
+    [AgentSkillScript("convert")]
+    [Description("Multiplies a value by a conversion factor and returns the result as JSON.")]
     private static string ConvertUnits(double value, double factor)
     {
         double result = Math.Round(value * factor, 4);

dotnet/samples/02-agents/AgentSkills/Agent_Step03_ClassBasedSkills/README.md

@@ -1,12 +1,16 @@
 # Class-Based Agent Skills Sample
 
-This sample demonstrates how to define **Agent Skills as C# classes** using `AgentClassSkill`.
+This sample demonstrates how to define **Agent Skills as C# classes** using `AgentClassSkill`
+with **attributes** for automatic script and resource discovery.
 
 ## What it demonstrates
 
 - Creating skills as classes that extend `AgentClassSkill`
-- Bundling name, description, body, resources, and scripts into a single class
+- Using `[AgentSkillResource]` on properties to define resources
+- Using `[AgentSkillScript]` on methods to define scripts
+- Automatic discovery (no need to override `Resources`/`Scripts`)
 - Using the `AgentSkillsProvider` constructor with class-based skills
+- Overriding `SerializerOptions` for Native AOT compatibility
 
 ## Skills Included
 

dotnet/samples/02-agents/AgentSkills/Agent_Step04_MixedSkills/Agent_Step04_MixedSkills.csproj

@@ -6,7 +6,7 @@
 
     <Nullable>enable</Nullable>
     <ImplicitUsings>enable</ImplicitUsings>
-    <NoWarn>$(NoWarn);MAAI001</NoWarn>
+    <NoWarn>$(NoWarn);MAAI001;IDE0051</NoWarn>
   </PropertyGroup>
 
   <ItemGroup>

dotnet/samples/02-agents/AgentSkills/Agent_Step04_MixedSkills/Program.cs

@@ -8,11 +8,12 @@
 // Three different skill sources are registered here:
 // 1. File-based: unit-converter (miles↔km, pounds↔kg) from SKILL.md on disk
 // 2. Code-defined: volume-converter (gallons↔liters) using AgentInlineSkill
-// 3. Class-based: temperature-converter (°F↔°C↔K) using AgentClassSkill
+// 3. Class-based: temperature-converter (°F↔°C↔K) using AgentClassSkill with attributes
 //
 // For simpler, single-source scenarios, see the earlier steps in this sample series
 // (e.g., Step01 for file-based, Step02 for code-defined, Step03 for class-based).
 
+using System.ComponentModel;
 using System.Text.Json;
 using Azure.AI.OpenAI;
 using Azure.Identity;
@@ -89,13 +90,15 @@ 1. Review the volume-conversion-table resource to find the correct factor.
 Console.WriteLine($"Agent: {response.Text}");
 
 /// <summary>
-/// A temperature-converter skill defined as a C# class.
+/// A temperature-converter skill defined as a C# class using attributes for discovery.
 /// </summary>
-internal sealed class TemperatureConverterSkill : AgentClassSkill
+/// <remarks>
+/// Properties annotated with <see cref="AgentSkillResourceAttribute"/> are automatically
+/// discovered as skill resources, and methods annotated with <see cref="AgentSkillScriptAttribute"/>
+/// are automatically discovered as skill scripts.
+/// </remarks>
+internal sealed class TemperatureConverterSkill : AgentClassSkill<TemperatureConverterSkill>
 {
-    private IReadOnlyList<AgentSkillResource>? _resources;
-    private IReadOnlyList<AgentSkillScript>? _scripts;
-
     /// <inheritdoc/>
     public override AgentSkillFrontmatter Frontmatter { get; } = new(
         "temperature-converter",
@@ -110,29 +113,27 @@ Use this skill when the user asks to convert temperatures.
         3. Present the result clearly with both temperature scales.
         """;
 
-    /// <inheritdoc/>
-    public override IReadOnlyList<AgentSkillResource>? Resources => this._resources ??=
-    [
-        CreateResource(
-            "temperature-conversion-formulas",
-            """
-            # Temperature Conversion Formulas
-
-            | From        | To          | Formula                   |
-            |-------------|-------------|---------------------------|
-            | Fahrenheit  | Celsius     | °C = (°F − 32) × 5/9     |
-            | Celsius     | Fahrenheit  | °F = (°C × 9/5) + 32     |
-            | Celsius     | Kelvin      | K = °C + 273.15           |
-            | Kelvin      | Celsius     | °C = K − 273.15           |
-            """),
-    ];
-
-    /// <inheritdoc/>
-    public override IReadOnlyList<AgentSkillScript>? Scripts => this._scripts ??=
-    [
-        CreateScript("convert-temperature", ConvertTemperature),
-    ];
+    /// <summary>
+    /// A reference table of temperature conversion formulas.
+    /// </summary>
+    [AgentSkillResource("temperature-conversion-formulas")]
+    [Description("Formulas for converting between Fahrenheit, Celsius, and Kelvin.")]
+    public string ConversionFormulas => """
+        # Temperature Conversion Formulas
+
+        | From        | To          | Formula                   |
+        |-------------|-------------|---------------------------|
+        | Fahrenheit  | Celsius     | °C = (°F − 32) × 5/9     |
+        | Celsius     | Fahrenheit  | °F = (°C × 9/5) + 32     |
+        | Celsius     | Kelvin      | K = °C + 273.15           |
+        | Kelvin      | Celsius     | °C = K − 273.15           |
+        """;
 
+    /// <summary>
+    /// Converts a temperature value between scales.
+    /// </summary>
+    [AgentSkillScript("convert-temperature")]
+    [Description("Converts a temperature value from one scale to another.")]
     private static string ConvertTemperature(double value, string from, string to)
     {
         double result = (from.ToUpperInvariant(), to.ToUpperInvariant()) switch

dotnet/samples/02-agents/AgentSkills/Agent_Step05_SkillsWithDI/Agent_Step05_SkillsWithDI.csproj

@@ -6,7 +6,7 @@
 
     <Nullable>enable</Nullable>
     <ImplicitUsings>enable</ImplicitUsings>
-    <NoWarn>$(NoWarn);MAAI001;CA1812</NoWarn>
+    <NoWarn>$(NoWarn);MAAI001;CA1812;IDE0051</NoWarn>
   </PropertyGroup>
 
   <ItemGroup>

dotnet/samples/02-agents/AgentSkills/Agent_Step05_SkillsWithDI/Program.cs

@@ -13,6 +13,7 @@
 // showing that DI works identically regardless of how the skill is defined.
 // When prompted with a question spanning both domains, the agent uses both skills.
 
+using System.ComponentModel;
 using System.Text.Json;
 using Azure.AI.OpenAI;
 using Azure.Identity;
@@ -62,8 +63,8 @@ Use this skill when the user asks to convert between distance units (miles and k
 // Approach 2: Class-Based Skill with DI (AgentClassSkill)
 // =====================================================================
 // Handles weight conversions (pounds ↔ kilograms).
-// Resources and scripts are encapsulated in a class. Factory methods
-// CreateResource and CreateScript accept delegates with IServiceProvider.
+// Resources and scripts are discovered via reflection using attributes.
+// Methods with an IServiceProvider parameter receive DI automatically.
 //
 // Alternatively, class-based skills can accept dependencies through their
 // constructor. Register the skill class itself in the ServiceCollection and
@@ -113,14 +114,13 @@ Use this skill when the user asks to convert between distance units (miles and k
 /// </summary>
 /// <remarks>
 /// This skill resolves <see cref="ConversionService"/> from the DI container
-/// in both its resource and script functions. This enables clean separation of
-/// concerns and testability while retaining the class-based skill pattern.
+/// in both its resource and script methods. Methods with an <see cref="IServiceProvider"/>
+/// parameter are automatically injected by the framework. Properties and methods annotated
+/// with <see cref="AgentSkillResourceAttribute"/> and <see cref="AgentSkillScriptAttribute"/>
+/// are automatically discovered via reflection.
 /// </remarks>
-internal sealed class WeightConverterSkill : AgentClassSkill
+internal sealed class WeightConverterSkill : AgentClassSkill<WeightConverterSkill>
 {
-    private IReadOnlyList<AgentSkillResource>? _resources;
-    private IReadOnlyList<AgentSkillScript>? _scripts;
-
     /// <inheritdoc/>
     public override AgentSkillFrontmatter Frontmatter { get; } = new(
         "weight-converter",
@@ -135,25 +135,27 @@ Use this skill when the user asks to convert between weight units (pounds and ki
         3. Present the result clearly with both units.
         """;
 
-    /// <inheritdoc/>
-    public override IReadOnlyList<AgentSkillResource>? Resources => this._resources ??=
-    [
-        CreateResource("weight-table", (IServiceProvider serviceProvider) =>
-        {
-            var service = serviceProvider.GetRequiredService<ConversionService>();
-            return service.GetWeightTable();
-        }),
-    ];
+    /// <summary>
+    /// Returns the weight conversion table from the DI-registered <see cref="ConversionService"/>.
+    /// </summary>
+    [AgentSkillResource("weight-table")]
+    [Description("Lookup table of multiplication factors for weight conversions.")]
+    private static string GetWeightTable(IServiceProvider serviceProvider)
+    {
+        var service = serviceProvider.GetRequiredService<ConversionService>();
+        return service.GetWeightTable();
+    }
 
-    /// <inheritdoc/>
-    public override IReadOnlyList<AgentSkillScript>? Scripts => this._scripts ??=
-    [
-        CreateScript("convert", (double value, double factor, IServiceProvider serviceProvider) =>
-        {
-            var service = serviceProvider.GetRequiredService<ConversionService>();
-            return service.Convert(value, factor);
-        }),
-    ];
+    /// <summary>
+    /// Converts a value by the given factor using the DI-registered <see cref="ConversionService"/>.
+    /// </summary>
+    [AgentSkillScript("convert")]
+    [Description("Multiplies a value by a conversion factor and returns the result as JSON.")]
+    private static string Convert(double value, double factor, IServiceProvider serviceProvider)
+    {
+        var service = serviceProvider.GetRequiredService<ConversionService>();
+        return service.Convert(value, factor);
+    }
 }
 
 // ---------------------------------------------------------------------------

dotnet/src/Microsoft.Agents.AI/Skills/AgentSkillsProviderBuilder.cs

@@ -21,7 +21,7 @@ namespace Microsoft.Agents.AI;
 /// </para>
 /// <list type="bullet">
 ///   <item><description><strong>Mixed skill types</strong> — combine file-based, code-defined (<see cref="AgentInlineSkill"/>),
-///   and class-based (<see cref="AgentClassSkill"/>) skills in a single provider.</description></item>
+///   and class-based (<see cref="AgentClassSkill{TSelf}"/>) skills in a single provider.</description></item>
 ///   <item><description><strong>Multiple file script runners</strong> — use different script runners for different
 ///   file skill directories via per-source <c>scriptRunner</c> parameters on
 ///   <see cref="UseFileSkill"/> / <see cref="UseFileSkills(IEnumerable{string}, AgentFileSkillsSourceOptions?, AgentFileSkillScriptRunner?)"/>.</description></item>