Set bounds for RetryPolicyOptions

core/Azure.Mcp.Core/src/Services/Azure/BaseAzureService.cs

@@ -13,6 +13,7 @@ namespace Azure.Mcp.Core.Services.Azure;
 
 public abstract class BaseAzureService
 {
+    private const int MaxAllowedRetries = 10;
     private static UserAgentPolicy s_sharedUserAgentPolicy;
     private static string? s_userAgent;
     private static volatile bool s_initialized = false;
@@ -198,7 +199,9 @@ protected static T ConfigureRetryPolicy<T>(T clientOptions, RetryPolicyOptions?
             }
             if (retryPolicy.HasMaxRetries)
             {
-                clientOptions.Retry.MaxRetries = retryPolicy.MaxRetries;
+                // To prevent excessive retries, we enforce a maximum number of retries regardless of what the caller specifies.
+                // This is to protect against misconfiguration that could lead to very long retry loops.
+                clientOptions.Retry.MaxRetries = Math.Min(MaxAllowedRetries, retryPolicy.MaxRetries);
             }
             if (retryPolicy.HasMode)
             {

core/Azure.Mcp.Core/tests/Azure.Mcp.Core.UnitTests/Services/Azure/BaseAzureServiceTests.cs

@@ -215,6 +215,24 @@ public async Task GetArmAccessTokenAsync_NullTenant_PassesNullToGetTokenCredenti
         await _tenantService.Received(1).GetTokenCredentialAsync(null, Arg.Any<CancellationToken>());
     }
 
+    [Theory]
+    [InlineData(5, true, 5)]   // below cap, should remain unchanged
+    [InlineData(10, true, 10)] // at cap, should remain unchanged
+    [InlineData(20, true, 10)] // above cap, should be capped
+    [InlineData(20, false, null)] // HasMaxRetries = false, should not override default
+    public void ConfigureRetryPolicy_RespectsAndCapsMaxRetries(int maxRetries, bool hasMaxRetries, int? expectedMaxRetries)
+    {
+        // Arrange
+        var retryPolicy = new RetryPolicyOptions { MaxRetries = maxRetries, HasMaxRetries = hasMaxRetries };
+        var clientOptions = new ArmClientOptions();
+        var defaultClientOptions = new ArmClientOptions();
+        // Act
+        _azureService.ConfigureRetryPolicyPublic(clientOptions, retryPolicy);
+        // Assert
+        var expected = expectedMaxRetries ?? defaultClientOptions.Retry.MaxRetries;
+        Assert.Equal(expected, clientOptions.Retry.MaxRetries);
+    }
+
     private sealed class TestAzureService(ITenantService tenantService) : BaseAzureService(tenantService)
     {
         public Task<ArmClient> GetArmClientAsync(string? tenant = null, RetryPolicyOptions? retryPolicy = null) =>
@@ -232,5 +250,8 @@ public Task<AccessToken> GetArmAccessTokenPublicAsync(string? tenant, Cancellati
         public string EscapeKqlStringTest(string value) => EscapeKqlString(value);
 
         public string GetUserAgent() => UserAgent;
+
+        public T ConfigureRetryPolicyPublic<T>(T clientOptions, RetryPolicyOptions? retryPolicy) where T : ClientOptions =>
+            ConfigureRetryPolicy(clientOptions, retryPolicy);
     }
 }

servers/Azure.Mcp.Server/changelog-entries/1774384466055.yaml

@@ -0,0 +1,4 @@
+pr: 2187
+changes:
+  - section: "Other Changes"
+    description: "Added bounds for RetryPolicyOptions"