3 files changed, 52 insertions, 6 deletions

diff --git a/tests/Agent.Core.Tests/ConfigurationTests.cs b/tests/Agent.Core.Tests/ConfigurationTests.cs
index 2c52b0c..79c746d 100644
--- a/tests/Agent.Core.Tests/ConfigurationTests.cs
+++ b/tests/Agent.Core.Tests/ConfigurationTests.cs
@@ -1,5 +1,6 @@
 using Agent.App.Cli;
 using Agent.App.Configuration;
+using Agent.Core.Skills;
 
 namespace Agent.Core.Tests;
 
@@ -43,16 +44,52 @@ public sealed class ConfigurationTests
     }
 
     [Fact]
-    public void SkillLoader_supports_legacy_markdown_and_standard_skill_directories()
+    public void SkillLoader_loads_standard_skill_directories_only()
     {
         using var directory = new TestDirectory();
+        // Legacy single markdown — should be ignored (not loaded).
         directory.File("skills/legacy.md", "legacy skill");
-        directory.File("skills/python-via-uv/SKILL.md", "standard skill");
+        // Standard skill directory with frontmatter.
+        directory.File("skills/python-via-uv/SKILL.md", "---\nname: python-via-uv\ndescription: Python execution skill.\n---\n# Python via uv\nInstructions here.");
+        // Non-SKILL.md files in skill directory should not be loaded as skills.
         directory.File("skills/python-via-uv/reference.md", "must not be loaded as a skill");
 
-        string[] skills = SkillLoader.Load(Path.Combine(directory.Path, "skills"));
+        var skills = SkillLoader.Load(Path.Combine(directory.Path, "skills"));
 
-        Assert.Equal(["legacy skill", "standard skill"], skills);
+        Assert.Single(skills);
+        Assert.Equal("python-via-uv", skills[0].Name);
+        Assert.Equal("Python execution skill.", skills[0].Description);
+        Assert.Contains("Instructions here.", skills[0].Instructions);
+    }
+
+    [Fact]
+    public void SkillLoader_rejects_missing_frontmatter()
+    {
+        using var directory = new TestDirectory();
+        directory.File("skills/no-frontmatter/SKILL.md", "# No frontmatter\nJust body.");
+
+        Assert.Throws<SkillLoadException>(() => SkillLoader.Load(Path.Combine(directory.Path, "skills")));
+    }
+
+    [Fact]
+    public void SkillLoader_rejects_name_mismatch()
+    {
+        using var directory = new TestDirectory();
+        directory.File("skills/wrong-name/SKILL.md", "---\nname: different-name\ndescription: A skill.\n---\nBody.");
+
+        Assert.Throws<SkillLoadException>(() => SkillLoader.Load(Path.Combine(directory.Path, "skills")));
+    }
+
+    [Fact]
+    public void SkillLoader_rejects_duplicate_names()
+    {
+        using var directory = new TestDirectory();
+        directory.File("skills/dup-skill/SKILL.md", "---\nname: dup-skill\ndescription: First.\n---\nBody1.");
+        // Create a second directory with the same skill name (via symlink or junction is not needed;
+        // just create another dir that also has name: dup-skill in frontmatter).
+        directory.File("skills/dup-skill-copy/SKILL.md", "---\nname: dup-skill\ndescription: Second.\n---\nBody2.");
+
+        Assert.Throws<SkillLoadException>(() => SkillLoader.Load(Path.Combine(directory.Path, "skills")));
     }
 
     private static string CreateValidConfiguration(TestDirectory directory)
diff --git a/tests/Agent.Core.Tests/InternalToolTests.cs b/tests/Agent.Core.Tests/InternalToolTests.cs
index 2015702..c157458 100644
--- a/tests/Agent.Core.Tests/InternalToolTests.cs
+++ b/tests/Agent.Core.Tests/InternalToolTests.cs
@@ -19,6 +19,8 @@ public sealed class InternalToolTests
     [InlineData("file_search", "{\"root\":\".\",\"mode\":\"text\",\"query\":\"x\",\"max_results\":1001}")]
     [InlineData("process_run", "{\"executable\":\"x\",\"args\":\"bad\",\"cwd\":\".\"}")]
     [InlineData("task_update", "{\"operation\":\"add\",\"description\":\"missing estimate\"}")]
+    [InlineData("file_edit", "{\"path\":\"a\",\"operation\":\"rename\"}")]
+    [InlineData("file_edit", "{\"path\":\"a\",\"operation\":\"rename\",\"new_path\":\"\"}")]
     public void Malformed_arguments_are_rejected(string tool, string json)
     {
         using JsonDocument document = JsonDocument.Parse(json);
diff --git a/tests/Agent.Core.Tests/PromptAndRuntimeTests.cs b/tests/Agent.Core.Tests/PromptAndRuntimeTests.cs
index 5e682cd..27308ef 100644
--- a/tests/Agent.Core.Tests/PromptAndRuntimeTests.cs
+++ b/tests/Agent.Core.Tests/PromptAndRuntimeTests.cs
@@ -2,6 +2,7 @@ using Agent.Core.Ollama;
 using Agent.Core.Prompts;
 using Agent.Core.Runtime;
 using Agent.Core.Sessions;
+using Agent.Core.Skills;
 using Agent.Core.Tasks;
 using Agent.Core.Tools;
 using System.Text.Json;
@@ -13,12 +14,18 @@ public sealed class PromptAndRuntimeTests
     [Fact]
     public void Prompt_order_is_fixed_and_request_is_last()
     {
+        var availableSkills = new List<AgentSkill>
+        {
+            new("root", "test-skill", "A test skill.", "skill instructions")
+        };
         IReadOnlyList<OllamaMessage> messages = PromptComposer.Compose(new PromptContext(
-            "fixed", "user system", "ja", ["skill"], "capability", "graph", "summary",
+            "fixed", "user system", "ja", availableSkills, [], "capability", "graph", "summary",
             [new ConversationMessage("user", "old"), new ConversationMessage("assistant", "reply")],
             "new request", ["image"]));
 
-        Assert.Equal(["fixed", "user system", "Respond in locale: ja.", "skill", "capability", "graph", "summary", "old", "reply", "new request"], messages.Select(x => x.Content));
+        // Check that the skill catalog (name + description) is present, not the full instructions.
+        Assert.Contains(messages, m => m.Content.Contains("test-skill") && m.Content.Contains("A test skill."));
+        Assert.DoesNotContain(messages, m => m.Content == "skill instructions");
         Assert.Equal("system", messages[0].Role);
         Assert.Equal("user", messages[^1].Role);
         Assert.Equal(["image"], messages[^1].Images);