1 files changed, 38 insertions, 2 deletions
diff --git a/tests/Agent.Core.Tests/InternalToolTests.cs b/tests/Agent.Core.Tests/InternalToolTests.cs
index e452cab..2015702 100644
--- a/tests/Agent.Core.Tests/InternalToolTests.cs
+++ b/tests/Agent.Core.Tests/InternalToolTests.cs
@@ -6,9 +6,9 @@ namespace Agent.Core.Tests;
 public sealed class InternalToolTests
 {
     [Fact]
-    public void Catalog_exposes_exactly_five_strict_tool_groups()
+    public void Catalog_exposes_six_strict_tool_groups()
     {
-        Assert.Equal(["file_search", "file_read", "file_edit", "process_run", "task_update"], InternalToolCatalog.All.Select(x => x.Name));
+        Assert.Equal(["file_search", "file_read", "file_edit", "process_run", "task_update", "dir"], InternalToolCatalog.All.Select(x => x.Name));
         foreach (InternalToolDefinition tool in InternalToolCatalog.All) Assert.False(tool.Parameters.GetProperty("additionalProperties").GetBoolean());
     }
 
@@ -86,4 +86,40 @@ public sealed class InternalToolTests
         handler.EndTask(scope);
         Assert.Throws<InvalidOperationException>(() => handler.Execute(scope, add.RootElement));
     }
+
+    [Theory]
+    [InlineData("dir", "{}")]
+    [InlineData("dir", """{"path":"x","operation":"invalid"}""")]
+    [InlineData("dir", """{"path":"x","operation":"mkdir","extra":1}""")]
+    [InlineData("dir", """{"operation":"mkdir"}""")]
+    public void Dir_malformed_arguments_are_rejected(string tool, string json)
+    {
+        using JsonDocument document = JsonDocument.Parse(json);
+        Assert.Throws<ToolValidationException>(() => InternalToolValidator.Validate(tool, document.RootElement));
+    }
+
+    [Fact]
+    public void Dir_catalog_definition_has_required_fields_and_strict_schema()
+    {
+        InternalToolDefinition definition = InternalToolCatalog.Get("dir");
+        Assert.Equal("dir", definition.Name);
+        Assert.False(definition.Parameters.GetProperty("additionalProperties").GetBoolean());
+        Assert.Equal(["path", "operation"], definition.Parameters.GetProperty("required").EnumerateArray().Select(r => r.GetString()!).ToArray());
+        Assert.Equal(["mkdir", "rmdir", "list"], definition.Parameters.GetProperty("properties").GetProperty("operation").GetProperty("enum").EnumerateArray().Select(v => v.GetString()!).ToArray());
+    }
+
+    [Fact]
+    public async Task Dir_dispatched_to_fake_backend_has_external_effect()
+    {
+        FakeInternalToolBackend backend = new();
+        InternalToolDispatcher dispatcher = new(new DenyByDefaultPolicy(new HashSet<string>(["dir"], StringComparer.Ordinal)), backend);
+        using JsonDocument document = JsonDocument.Parse("""{"path":"C:\\tmp\\sub","operation":"mkdir"}""");
+
+        ToolExecutionResult result = await dispatcher.DispatchAsync(Guid.NewGuid(), "dir", document.RootElement, TestContext.Current.CancellationToken);
+
+        Assert.True(result.Success);
+        Assert.True(result.ExternalEffect);
+        Assert.Single(backend.Calls);
+        Assert.Equal("dir", backend.Calls[0].Name);
+    }
 }