From 8a18f39b367c21908e0f55c43a891490df088ec6 Mon Sep 17 00:00:00 2001
From: SergeyMenshykh <68852919+SergeyMenshykh@users.noreply.github.com>
Date: Mon, 2 Mar 2026 16:48:10 +0000
Subject: [PATCH] fix the issue (#4388)

---
 .../src/Microsoft.Agents.AI/Skills/FileAgentSkillsProvider.cs  | 3 ++-
 .../AgentSkills/FileAgentSkillsProviderTests.cs                | 2 ++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/dotnet/src/Microsoft.Agents.AI/Skills/FileAgentSkillsProvider.cs b/dotnet/src/Microsoft.Agents.AI/Skills/FileAgentSkillsProvider.cs
index 847bf36a52..ad1ef752ee 100644
--- a/dotnet/src/Microsoft.Agents.AI/Skills/FileAgentSkillsProvider.cs
+++ b/dotnet/src/Microsoft.Agents.AI/Skills/FileAgentSkillsProvider.cs
@@ -174,7 +174,8 @@ public sealed partial class FileAgentSkillsProvider : AIContextProvider
         {
             try
             {
-                promptTemplate = string.Format(optionsInstructions, string.Empty);
+                _ = string.Format(optionsInstructions, string.Empty);
+                promptTemplate = optionsInstructions;
             }
             catch (FormatException ex)
             {
diff --git a/dotnet/tests/Microsoft.Agents.AI.UnitTests/AgentSkills/FileAgentSkillsProviderTests.cs b/dotnet/tests/Microsoft.Agents.AI.UnitTests/AgentSkills/FileAgentSkillsProviderTests.cs
index 6bfaf1b546..92dc5a5418 100644
--- a/dotnet/tests/Microsoft.Agents.AI.UnitTests/AgentSkills/FileAgentSkillsProviderTests.cs
+++ b/dotnet/tests/Microsoft.Agents.AI.UnitTests/AgentSkills/FileAgentSkillsProviderTests.cs
@@ -108,6 +108,8 @@ public sealed class FileAgentSkillsProviderTests : IDisposable
         // Assert
         Assert.NotNull(result.Instructions);
         Assert.StartsWith("Custom template:", result.Instructions);
+        Assert.Contains("custom-prompt-skill", result.Instructions);
+        Assert.Contains("Custom prompt", result.Instructions);
     }
 
     [Fact]