Fix SA1614: Add text to empty parameter documentation (#46706)

Add meaningful descriptions to 3 empty param XML doc tags in
BaseDscTest.cs and ShellHelpers.cs.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/dsc/v3/PowerToys.DSC.UnitTests/BaseDscTest.cs

@@ -36,7 +36,7 @@ public class BaseDscTest
     /// Execute a dsc command with the provided arguments.
     /// </summary>
     /// <typeparam name="T">The type of the DSC command to execute.</typeparam>
-    /// <param name="args"></param>
+    /// <param name="args">The command-line arguments to pass to the DSC command.</param>
     /// <returns>The result of the DSC command execution.</returns>
     protected DscExecuteResult ExecuteDscCommand<T>(params string[] args)
         where T : Command, new()

src/modules/cmdpal/extensionsdk/Microsoft.CommandPalette.Extensions.Toolkit/ShellHelpers.cs

@@ -246,8 +246,8 @@ public static class ShellHelpers
     /// <summary>
     /// Mimics Windows Shell behavior to resolve an executable name to a full path.
     /// </summary>
-    /// <param name="name"></param>
-    /// <param name="fullPath"></param>
+    /// <param name="name">The name of the executable to resolve.</param>
+    /// <param name="fullPath">When this method returns, contains the full path to the executable if found; otherwise, <see langword="null"/>.</param>
     /// <returns><see langword="true"/> if the executable was resolved to a full path; otherwise, <see langword="false"/>.</returns>
     public static bool TryResolveExecutableAsShell(string name, out string fullPath)
     {