diff --git a/src/Libraries/Microsoft.Extensions.AI.Abstractions/Utilities/AIJsonUtilities.Schema.Create.cs b/src/Libraries/Microsoft.Extensions.AI.Abstractions/Utilities/AIJsonUtilities.Schema.Create.cs
index c77e7dffb5b..17e5e4d5353 100644
--- a/src/Libraries/Microsoft.Extensions.AI.Abstractions/Utilities/AIJsonUtilities.Schema.Create.cs
+++ b/src/Libraries/Microsoft.Extensions.AI.Abstractions/Utilities/AIJsonUtilities.Schema.Create.cs
@@ -14,6 +14,7 @@
 using System.Text.Json.Nodes;
 using System.Text.Json.Schema;
 using System.Text.Json.Serialization;
+using System.Text.Json.Serialization.Metadata;
 using System.Threading;
 using Microsoft.Shared.Diagnostics;
 
@@ -289,6 +290,12 @@ JsonNode TransformSchemaNode(JsonSchemaExporterContext schemaExporterContext, Js
                     objSchema.InsertAtStart(TypePropertyName, "string");
                 }
 
+                // Include a trivial items keyword if missing
+                if (ctx.TypeInfo.Kind is JsonTypeInfoKind.Enumerable && !objSchema.ContainsKey(ItemsPropertyName))
+                {
+                    objSchema.Add(ItemsPropertyName, new JsonObject());
+                }
+
                 // Some consumers of the JSON schema, including Ollama as of v0.3.13, don't understand
                 // schemas with "type": [...], and only understand "type" being a single value.
                 // In certain configurations STJ represents .NET numeric types as ["string", "number"], which will then lead to an error.
diff --git a/test/Libraries/Microsoft.Extensions.AI.Abstractions.Tests/Utilities/AIJsonUtilitiesTests.cs b/test/Libraries/Microsoft.Extensions.AI.Abstractions.Tests/Utilities/AIJsonUtilitiesTests.cs
index acbb5515085..bcec2981c5b 100644
--- a/test/Libraries/Microsoft.Extensions.AI.Abstractions.Tests/Utilities/AIJsonUtilitiesTests.cs
+++ b/test/Libraries/Microsoft.Extensions.AI.Abstractions.Tests/Utilities/AIJsonUtilitiesTests.cs
@@ -170,6 +170,21 @@ public static void CreateJsonSchema_DefaultParameters_GeneratesExpectedJsonSchem
         AssertDeepEquals(expected, actual);
     }
 
+    [Fact]
+    public static void CreateJsonSchema_TrivialArray_GeneratesExpectedJsonSchema()
+    {
+        JsonElement expected = JsonDocument.Parse("""
+            {
+                "type": "array",
+                "items": {}
+            }
+            """).RootElement;
+
+        JsonElement actual = AIJsonUtilities.CreateJsonSchema(typeof(object[]), serializerOptions: JsonContext.Default.Options);
+
+        AssertDeepEquals(expected, actual);
+    }
+
     [Fact]
     public static void CreateJsonSchema_OverriddenParameters_GeneratesExpectedJsonSchema()
     {
@@ -1326,6 +1341,7 @@ private class DerivedAIContent : AIContent
     [JsonSerializable(typeof(DerivedAIContent))]
     [JsonSerializable(typeof(MyPoco))]
     [JsonSerializable(typeof(MyEnumValue?))]
+    [JsonSerializable(typeof(object[]))]
     private partial class JsonContext : JsonSerializerContext;
 
     private static bool DeepEquals(JsonElement element1, JsonElement element2)