New Tool: List Event Grid Subscription

Directory.Packages.props

@@ -62,8 +62,7 @@
     <PackageVersion Include="ModelContextProtocol.AspNetCore" Version="0.3.0-preview.4" />
     <PackageVersion Include="Microsoft.Extensions.Caching.Memory" Version="9.0.6" />
     <PackageVersion Include="Microsoft.Extensions.Configuration" Version="9.0.6" />
-    <PackageVersion Include="Microsoft.Extensions.Configuration.EnvironmentVariables"
-      Version="9.0.6" />
+    <PackageVersion Include="Microsoft.Extensions.Configuration.EnvironmentVariables" Version="9.0.6" />
     <PackageVersion Include="Microsoft.Extensions.Configuration.Json" Version="9.0.6" />
     <PackageVersion Include="Microsoft.HybridRow" Version="1.1.0-preview3" />
     <PackageVersion Include="Microsoft.Azure.Cosmos.Aot" Version="0.1.2-preview.2" />
@@ -95,4 +94,4 @@
     <PackageVersion Include="coverlet.collector" Version="6.0.2" />
     <!-- Pin to 6.0.2 until https://github.com/coverlet-coverage/coverlet/issues/1737 is resolved -->
   </ItemGroup>
-</Project>
+</Project>

core/Azure.Mcp.Core/src/Commands/Subscription/SubscriptionCommand.cs

@@ -1,7 +1,9 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT License.
 
+using System.CommandLine.Parsing;
 using System.Diagnostics.CodeAnalysis;
+using Azure.Mcp.Core.Helpers;
 using Azure.Mcp.Core.Models.Option;
 using Azure.Mcp.Core.Options;
 
@@ -20,9 +22,7 @@ protected override void RegisterOptions(Command command)
         // This mirrors the prior behavior that preferred the explicit option but fell back to env var.
         command.Validators.Add(commandResult =>
         {
-            var hasOption = commandResult.HasOptionResult(OptionDefinitions.Common.Subscription.Name);
-            var hasEnv = !string.IsNullOrEmpty(Environment.GetEnvironmentVariable("AZURE_SUBSCRIPTION_ID"));
-            if (!hasOption && !hasEnv)
+            if (!HasSubscriptionAvailable(commandResult))
             {
                 commandResult.AddError("Missing Required options: --subscription");
             }
@@ -36,7 +36,7 @@ protected override TOptions BindOptions(ParseResult parseResult)
         // Get subscription from command line option or fallback to environment variable
         var subscriptionValue = parseResult.GetValueOrDefault<string>(OptionDefinitions.Common.Subscription.Name);
 
-        var envSubscription = Environment.GetEnvironmentVariable("AZURE_SUBSCRIPTION_ID");
+        var envSubscription = EnvironmentHelpers.GetAzureSubscriptionId();
         options.Subscription = (string.IsNullOrEmpty(subscriptionValue)
             || IsPlaceholder(subscriptionValue))
             && !string.IsNullOrEmpty(envSubscription)
@@ -46,6 +46,18 @@ protected override TOptions BindOptions(ParseResult parseResult)
         return options;
     }
 
+    /// <summary>
+    /// Checks if a subscription is available either from the command option or AZURE_SUBSCRIPTION_ID environment variable.
+    /// </summary>
+    /// <param name="commandResult">The command result to check for the subscription option.</param>
+    /// <returns>True if a subscription is available, false otherwise.</returns>
+    protected static bool HasSubscriptionAvailable(CommandResult commandResult)
+    {
+        var hasOption = commandResult.HasOptionResult(OptionDefinitions.Common.Subscription);
+        var hasEnv = !string.IsNullOrEmpty(EnvironmentHelpers.GetAzureSubscriptionId());
+        return hasOption || hasEnv;
+    }
+
     private static bool IsPlaceholder(string value)
         => value.Contains("subscription") || value.Contains("default");
 }

core/Azure.Mcp.Core/src/Helpers/EnvironmentVariableHelpers.cs

@@ -5,6 +5,8 @@ namespace Azure.Mcp.Core.Helpers
 {
     public static class EnvironmentHelpers
     {
+        private const string AzureSubscriptionIdEnvironmentVariable = "AZURE_SUBSCRIPTION_ID";
+
         public static bool GetEnvironmentVariableAsBool(string envVarName)
         {
             return Environment.GetEnvironmentVariable(envVarName) switch
@@ -16,5 +18,24 @@ public static bool GetEnvironmentVariableAsBool(string envVarName)
                 _ => false
             };
         }
+
+        /// <summary>
+        /// Gets the Azure subscription ID from the AZURE_SUBSCRIPTION_ID environment variable.
+        /// </summary>
+        /// <returns>The subscription ID if available, null otherwise.</returns>
+        public static string? GetAzureSubscriptionId()
+        {
+            return Environment.GetEnvironmentVariable(AzureSubscriptionIdEnvironmentVariable);
+        }
+
+        /// <summary>
+        /// Sets the AZURE_SUBSCRIPTION_ID environment variable. 
+        /// This method is primarily intended for testing scenarios.
+        /// </summary>
+        /// <param name="subscriptionId">The subscription ID to set, or null to clear the variable.</param>
+        public static void SetAzureSubscriptionId(string? subscriptionId)
+        {
+            Environment.SetEnvironmentVariable(AzureSubscriptionIdEnvironmentVariable, subscriptionId);
+        }
     }
 }

core/Azure.Mcp.Core/tests/Azure.Mcp.Core.UnitTests/Areas/Subscription/SubscriptionCommandTests.cs

@@ -2,6 +2,7 @@
 // Licensed under the MIT License.
 
 using System.CommandLine;
+using Azure.Mcp.Core.Helpers;
 using Azure.Mcp.Core.Models.Command;
 using Azure.Mcp.Core.Options;
 using Azure.Mcp.Tools.Storage.Commands.Account;
@@ -40,9 +41,8 @@ public SubscriptionCommandTests()
     public void Validate_WithEnvironmentVariableOnly_PassesValidation()
     {
         // Arrange
-        var originalValue = Environment.GetEnvironmentVariable("AZURE_SUBSCRIPTION_ID");
-        Environment.SetEnvironmentVariable("AZURE_SUBSCRIPTION_ID", "env-subs");
-
+        var originalValue = EnvironmentHelpers.GetAzureSubscriptionId();
+        EnvironmentHelpers.SetAzureSubscriptionId("env-subs");
         try
         {
             var parseResult = _commandDefinition.Parse([]);
@@ -53,16 +53,16 @@ public void Validate_WithEnvironmentVariableOnly_PassesValidation()
         finally
         {
             // Cleanup
-            Environment.SetEnvironmentVariable("AZURE_SUBSCRIPTION_ID", originalValue);
+            EnvironmentHelpers.SetAzureSubscriptionId(originalValue);
         }
     }
 
     [Fact]
     public async Task ExecuteAsync_WithEnvironmentVariableOnly_CallsServiceWithCorrectSubscription()
     {
         // Arrange
-        var originalValue = Environment.GetEnvironmentVariable("AZURE_SUBSCRIPTION_ID");
-        Environment.SetEnvironmentVariable("AZURE_SUBSCRIPTION_ID", "env-subs");
+        var originalValue = EnvironmentHelpers.GetAzureSubscriptionId();
+        EnvironmentHelpers.SetAzureSubscriptionId("env-subs");
 
         try
         {
@@ -97,16 +97,16 @@ public async Task ExecuteAsync_WithEnvironmentVariableOnly_CallsServiceWithCorre
         finally
         {
             // Cleanup
-            Environment.SetEnvironmentVariable("AZURE_SUBSCRIPTION_ID", originalValue);
+            EnvironmentHelpers.SetAzureSubscriptionId(originalValue);
         }
     }
 
     [Fact]
     public async Task ExecuteAsync_WithBothOptionAndEnvironmentVariable_PrefersOption()
     {
         // Arrange
-        var originalValue = Environment.GetEnvironmentVariable("AZURE_SUBSCRIPTION_ID");
-        Environment.SetEnvironmentVariable("AZURE_SUBSCRIPTION_ID", "env-subs");
+        var originalValue = EnvironmentHelpers.GetAzureSubscriptionId();
+        EnvironmentHelpers.SetAzureSubscriptionId("env-subs");
 
         try
         {
@@ -146,7 +146,7 @@ public async Task ExecuteAsync_WithBothOptionAndEnvironmentVariable_PrefersOptio
         finally
         {
             // Cleanup
-            Environment.SetEnvironmentVariable("AZURE_SUBSCRIPTION_ID", originalValue);
+            EnvironmentHelpers.SetAzureSubscriptionId(originalValue);
         }
     }
 }

docs/azmcp-commands.md

@@ -478,6 +478,13 @@ azmcp deploy plan get --workspace-folder <workspace-folder> \
 # List all Event Grid topics in a subscription or resource group
 azmcp eventgrid topic list --subscription <subscription> \
                            [--resource-group <resource-group>]
+
+
+# List all Event Grid subscriptions in a subscription, resource group, or topic
+azmcp eventgrid subscription list --subscription <subscription> \
+                                  [--resource-group <resource-group>] \
+                                  [--topic <topic>]
+                                  [--location <location>]
 ```
 
 ### Azure Function App Operations

docs/e2eTestPrompts.md

@@ -146,6 +146,13 @@ This file contains prompts used for end-to-end testing to ensure each tool is in
 | azmcp_eventgrid_topic_list | Show me the Event Grid topics in my subscription |
 | azmcp_eventgrid_topic_list | List all Event Grid topics in subscription <subscription> |
 | azmcp_eventgrid_topic_list | List all Event Grid topics in resource group <resource_group_name> in subscription <subscription> |
+| azmcp_eventgrid_subscription_list | Show me all Event Grid subscriptions for topic <topic_name> |
+| azmcp_eventgrid_subscription_list | List Event Grid subscriptions for topic <topic_name> in subscription <subscription> |
+| azmcp_eventgrid_subscription_list | List Event Grid subscriptions for topic <topic_name> in resource group <resource_group_name> |
+| azmcp_eventgrid_subscription_list | Show all Event Grid subscriptions in my subscription |
+| azmcp_eventgrid_subscription_list | List all Event Grid subscriptions in subscription <subscription> |
+| azmcp_eventgrid_subscription_list | Show Event Grid subscriptions in resource group <resource_group_name> in subscription <subscription> |
+| azmcp_eventgrid_subscription_list | List Event Grid subscriptions for subscription <subscription> in location <location> |
 
 ## Azure Function App
 

servers/Azure.Mcp.Server/README.md

@@ -98,7 +98,11 @@ The Azure MCP Server supercharges your agents with Azure context. Here are some
 
 * "List all Event Grid topics in subscription 'my-subscription'"
 * "Show me the Event Grid topics in my subscription"
-* "List all Event Grid topics in resource group 'my-resource-group' in my subscription"
+* "List all Event Grid topics in resource group 'my-resourcegroup' in my subscription"
+* "List Event Grid subscriptions for topic 'my-topic' in resource group 'my-resourcegroup'"
+* "List Event Grid subscriptions for topic 'my-topic' in subscription 'my-subscription'"
+* "List Event Grid Subscriptions in subscription 'my-subscription'"
+* "List Event Grid subscriptions for topic 'my-topic' in location 'my-location'"
 
 ### ⚡ Azure Managed Lustre
 
@@ -211,6 +215,8 @@ The Azure MCP Server supercharges your agents with Azure context. Here are some
 * List Event Grid topics in subscription or resource group
 * View topic configuration and status information
 * Access endpoint and key details for event publishing
+* List Event Grid subscriptions with filtering by topic name, resource group, and location
+* View subscription details including destination endpoints and retry policies
 
 ### 🧮 Azure Foundry
 

tools/Azure.Mcp.Tools.Acr/tests/Azure.Mcp.Tools.Acr.UnitTests/Registry/RegistryListCommandTests.cs

@@ -3,6 +3,7 @@
 
 using System.CommandLine;
 using System.Text.Json;
+using Azure.Mcp.Core.Helpers;
 using Azure.Mcp.Core.Models.Command;
 using Azure.Mcp.Core.Options;
 using Azure.Mcp.Tools.Acr.Commands;
@@ -52,7 +53,7 @@ public void Constructor_InitializesCommandCorrectly()
     public async Task ExecuteAsync_ValidatesInputCorrectly(string args, bool shouldSucceed)
     {
         // Ensure environment variable fallback does not interfere with validation tests
-        Environment.SetEnvironmentVariable("AZURE_SUBSCRIPTION_ID", null);
+        EnvironmentHelpers.SetAzureSubscriptionId(null);
         // Arrange
         if (shouldSucceed)
         {

tools/Azure.Mcp.Tools.EventGrid/src/Commands/EventGridJsonContext.cs

@@ -2,13 +2,16 @@
 // Licensed under the MIT License.
 
 using System.Text.Json.Serialization;
+using Azure.Mcp.Tools.EventGrid.Commands.Subscription;
 using Azure.Mcp.Tools.EventGrid.Commands.Topic;
 
 namespace Azure.Mcp.Tools.EventGrid.Commands;
 
+[JsonSerializable(typeof(SubscriptionListCommand.SubscriptionListCommandResult))]
 [JsonSerializable(typeof(TopicListCommand.TopicListCommandResult))]
+[JsonSerializable(typeof(EventGridSubscriptionInfo))]
 [JsonSerializable(typeof(EventGridTopicInfo))]
-[JsonSourceGenerationOptions(PropertyNamingPolicy = JsonKnownNamingPolicy.CamelCase)]
+[JsonSourceGenerationOptions(PropertyNamingPolicy = JsonKnownNamingPolicy.CamelCase, WriteIndented = true, DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull)]
 internal sealed partial class EventGridJsonContext : JsonSerializerContext
 {
 }