Update docs for JScriptEvaluate (#11180)

Author: krwq

Diff for: xml/Microsoft.JScript/Eval.xml

@@ -84,7 +84,13 @@
       </Parameters>
       <Docs>
         <param name="source">The code to evaluate.</param>
-        <param name="unsafeOption">The string literal <c>unsafe</c> to enable unsafe evaluation; otherwise, <see langword="false" />.</param>
+        <param name="unsafeOption">
+          The string literal <c>unsafe</c> to enable unsafe evaluation; otherwise, <see langword="false" />.
+          <para>
+            <b>Important:</b> This parameter is not intended to serve as a security boundary. 
+            Using <c>unsafeOption</c> should not be considered a substitute for proper security practices.
+          </para>
+        </param>
         <param name="engine">A reference to the scripting engine to use to evaluate <paramref name="source" />.</param>
         <summary>Evaluates the specified JScript code by using the specified engine and safety option.</summary>
         <returns>The result of the evaluation. If <paramref name="source" /> is not a string, return value is <paramref name="source" />.</returns>