diff --git a/xml/System.Threading/EventWaitHandleAcl.xml b/xml/System.Threading/EventWaitHandleAcl.xml
index 898e5dcd62a..7a8ed68b3af 100644
--- a/xml/System.Threading/EventWaitHandleAcl.xml
+++ b/xml/System.Threading/EventWaitHandleAcl.xml
@@ -1,4 +1,4 @@
-<Type Name="EventWaitHandleAcl" FullName="System.Threading.EventWaitHandleAcl">
+<Type Name="EventWaitHandleAcl" FullName="System.Threading.EventWaitHandleAcl">
   <TypeSignature Language="C#" Value="public static class EventWaitHandleAcl" />
   <TypeSignature Language="ILAsm" Value=".class public auto ansi abstract sealed beforefieldinit EventWaitHandleAcl extends System.Object" />
   <TypeSignature Language="DocId" Value="T:System.Threading.EventWaitHandleAcl" />
@@ -14,7 +14,7 @@
   </Base>
   <Interfaces />
   <Docs>
-    <summary>To be added.</summary>
+    <summary>Provides a Windows-specific extension method for creating <see cref="T:System.Threading.EventWaitHandle" /> objects with specific access control list (ACL) security.</summary>
     <remarks>To be added.</remarks>
   </Docs>
   <Members>
diff --git a/xml/System.Threading/MutexAcl.xml b/xml/System.Threading/MutexAcl.xml
index 30dbe51ecc3..79091151f48 100644
--- a/xml/System.Threading/MutexAcl.xml
+++ b/xml/System.Threading/MutexAcl.xml
@@ -1,4 +1,4 @@
-<Type Name="MutexAcl" FullName="System.Threading.MutexAcl">
+<Type Name="MutexAcl" FullName="System.Threading.MutexAcl">
   <TypeSignature Language="C#" Value="public static class MutexAcl" />
   <TypeSignature Language="ILAsm" Value=".class public auto ansi abstract sealed beforefieldinit MutexAcl extends System.Object" />
   <TypeSignature Language="DocId" Value="T:System.Threading.MutexAcl" />
@@ -14,7 +14,7 @@
   </Base>
   <Interfaces />
   <Docs>
-    <summary>To be added.</summary>
+    <summary>Provides a Windows-specific extension method for creating <see cref="T:System.Threading.Mutex" /> objects with specific access control list (ACL) security.</summary>
     <remarks>To be added.</remarks>
   </Docs>
   <Members>
diff --git a/xml/System.Threading/SemaphoreAcl.xml b/xml/System.Threading/SemaphoreAcl.xml
index 249cbde921d..18f95abf377 100644
--- a/xml/System.Threading/SemaphoreAcl.xml
+++ b/xml/System.Threading/SemaphoreAcl.xml
@@ -1,4 +1,4 @@
-<Type Name="SemaphoreAcl" FullName="System.Threading.SemaphoreAcl">
+<Type Name="SemaphoreAcl" FullName="System.Threading.SemaphoreAcl">
   <TypeSignature Language="C#" Value="public static class SemaphoreAcl" />
   <TypeSignature Language="ILAsm" Value=".class public auto ansi abstract sealed beforefieldinit SemaphoreAcl extends System.Object" />
   <TypeSignature Language="DocId" Value="T:System.Threading.SemaphoreAcl" />
@@ -14,7 +14,7 @@
   </Base>
   <Interfaces />
   <Docs>
-    <summary>To be added.</summary>
+    <summary>Provides a Windows-specific extension method for creating <see cref="T:System.Threading.Semaphore" /> objects with specific access control list (ACL) security.</summary>
     <remarks>To be added.</remarks>
   </Docs>
   <Members>
diff --git a/xml/System.Threading/ThreadingAclExtensions.xml b/xml/System.Threading/ThreadingAclExtensions.xml
index a0dc7ccfcbe..aab629eceda 100644
--- a/xml/System.Threading/ThreadingAclExtensions.xml
+++ b/xml/System.Threading/ThreadingAclExtensions.xml
@@ -24,7 +24,7 @@
     </Attribute>
   </Attributes>
   <Docs>
-    <summary>To be added.</summary>
+    <summary>Provides Windows-specific extension methods for managing the access control list (ACL) security descriptors for <see cref="T:System.Threading.EventWaitHandle" />, <see cref="T:System.Threading.Mutex" />, and <see cref="T:System.Threading.Semaphore" />.</summary>
     <remarks>To be added.</remarks>
   </Docs>
   <Members>
@@ -52,9 +52,9 @@
         <Parameter Name="handle" Type="System.Threading.EventWaitHandle" RefType="this" />
       </Parameters>
       <Docs>
-        <param name="handle">To be added.</param>
-        <summary>To be added.</summary>
-        <returns>To be added.</returns>
+        <param name="handle">The event wait handle from which the security descriptors should be returned.</param>
+        <summary>Returns the security descriptors for the specified <paramref name="handle" />.</summary>
+        <returns>The security descriptors for the specified <paramref name="handle" />.</returns>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>
@@ -82,9 +82,9 @@
         <Parameter Name="mutex" Type="System.Threading.Mutex" RefType="this" />
       </Parameters>
       <Docs>
-        <param name="mutex">To be added.</param>
-        <summary>To be added.</summary>
-        <returns>To be added.</returns>
+        <param name="mutex">The mutex from which the security descriptors should be returned.</param>
+        <summary>Returns the security descriptors for the specified <paramref name="mutex" />.</summary>
+        <returns>The security descriptors for the specified <paramref name="mutex" />.</returns>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>
@@ -112,9 +112,9 @@
         <Parameter Name="semaphore" Type="System.Threading.Semaphore" RefType="this" />
       </Parameters>
       <Docs>
-        <param name="semaphore">To be added.</param>
-        <summary>To be added.</summary>
-        <returns>To be added.</returns>
+        <param name="semaphore">The semaphore from which the security descriptors should be returned.</param>
+        <summary>Returns the security descriptors for the specified <paramref name="semaphore" />.</summary>
+        <returns>The security descriptors for the specified semaphore.</returns>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>
@@ -143,10 +143,12 @@
         <Parameter Name="eventSecurity" Type="System.Security.AccessControl.EventWaitHandleSecurity" />
       </Parameters>
       <Docs>
-        <param name="handle">To be added.</param>
-        <param name="eventSecurity">To be added.</param>
-        <summary>To be added.</summary>
+        <param name="handle">The event wait handle onto which the <paramref name="eventSecurity" /> will be applied.</param>
+        <param name="eventSecurity">The security descriptors to apply to the specified <paramref name="handle" />.</param>
+        <summary>Sets the security descriptors for the specified event wait handle.</summary>
         <remarks>To be added.</remarks>
+        <exception cref="T:System.ArgumentNullException">
+          <paramref name="eventSecurity" /> is <see langword="null" />.</exception>
       </Docs>
     </Member>
     <Member MemberName="SetAccessControl">
@@ -174,10 +176,12 @@
         <Parameter Name="mutexSecurity" Type="System.Security.AccessControl.MutexSecurity" />
       </Parameters>
       <Docs>
-        <param name="mutex">To be added.</param>
-        <param name="mutexSecurity">To be added.</param>
-        <summary>To be added.</summary>
+        <param name="mutex">The mutex onto which the <paramref name="mutexSecurity" /> will be applied.</param>
+        <param name="mutexSecurity">The security descriptors to apply to the specified <paramref name="mutex" />.</param>
+        <summary>Sets the security descriptors for the specified mutex.</summary>
         <remarks>To be added.</remarks>
+        <exception cref="T:System.ArgumentNullException">
+          <paramref name="mutexSecurity" /> is <see langword="null" />.</exception>
       </Docs>
     </Member>
     <Member MemberName="SetAccessControl">
@@ -205,10 +209,12 @@
         <Parameter Name="semaphoreSecurity" Type="System.Security.AccessControl.SemaphoreSecurity" />
       </Parameters>
       <Docs>
-        <param name="semaphore">To be added.</param>
-        <param name="semaphoreSecurity">To be added.</param>
-        <summary>To be added.</summary>
+        <param name="semaphore">The semaphore onto which the <paramref name="semaphoreSecurity" /> will be applied.</param>
+        <param name="semaphoreSecurity">The security descriptors to apply to the specified <paramref name="semaphore" />.</param>
+        <summary>Sets the security descriptors for the specified semaphore.</summary>
         <remarks>To be added.</remarks>
+        <exception cref="T:System.ArgumentNullException">
+          <paramref name="semaphoreSecurity" /> is <see langword="null" />.</exception>
       </Docs>
     </Member>
   </Members>