Improve CallerArgumentExpressionAttribute (#7338)

Author: gewarren

xml/System.Runtime.CompilerServices/CallerArgumentExpressionAttribute.xml

@@ -23,8 +23,15 @@
     </Attribute>
   </Attributes>
   <Docs>
-    <summary>Allows capturing of the expressions passed to a method. NOTE: Is not yet implemented in C# compiler and does nothing.</summary>
-    <remarks>To be added.</remarks>
+    <summary>Indicates that a parameter captures the expression passed for another parameter as a string.</summary>
+    <remarks>
+      <format type="text/markdown"><![CDATA[
+
+> [!NOTE]
+> This attribute is not yet implemented in the C# compiler and does nothing.
+
+]]></format>
+    </remarks>
   </Docs>
   <Members>
     <Member MemberName=".ctor">
@@ -46,7 +53,7 @@
         <Parameter Name="parameterName" Type="System.String" />
       </Parameters>
       <Docs>
-        <param name="parameterName">The name of the targeted parameter.</param>
+        <param name="parameterName">The name of the parameter whose expression should be captured as a string.</param>
         <summary>Initializes a new instance of the <see cref="T:System.Runtime.CompilerServices.CallerArgumentExpressionAttribute" /> class.</summary>
         <remarks>To be added.</remarks>
       </Docs>
@@ -70,9 +77,10 @@
         <ReturnType>System.String</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>Gets the target parameter name of the CallerArgumentExpression.</summary>
-        <value>The name of the targeted parameter of the CallerArgumentExpression.</value>
+        <summary>Gets the name of the parameter whose expression should be captured as a string.</summary>
+        <value>The name of the parameter whose expression should be captured.</value>
         <remarks>To be added.</remarks>
+        <related type="Article" href="/dotnet/csharp/language-reference/proposals/csharp-10.0/caller-argument-expression">C# CallerArgumentExpression proposal</related>
       </Docs>
     </Member>
   </Members>