diff --git a/xml/System.Text.Json.Serialization/JsonConstructorAttribute.xml b/xml/System.Text.Json.Serialization/JsonConstructorAttribute.xml
index 357400516ca..cf347408b9e 100644
--- a/xml/System.Text.Json.Serialization/JsonConstructorAttribute.xml
+++ b/xml/System.Text.Json.Serialization/JsonConstructorAttribute.xml
@@ -20,7 +20,7 @@
     </Attribute>
   </Attributes>
   <Docs>
-    <summary>To be added.</summary>
+    <summary>When placed on a constructor, indicates that the constructor should be used to create instances of the type on deserialization.</summary>
     <remarks>To be added.</remarks>
   </Docs>
   <Members>
@@ -37,7 +37,7 @@
       </AssemblyInfo>
       <Parameters />
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Initializes a new instance of <see cref="T:System.Text.Json.Serialization.JsonConstructorAttribute" />.</summary>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>
diff --git a/xml/System.Text.Json.Serialization/JsonIgnoreAttribute.xml b/xml/System.Text.Json.Serialization/JsonIgnoreAttribute.xml
index f835717cd87..71d494fa051 100644
--- a/xml/System.Text.Json.Serialization/JsonIgnoreAttribute.xml
+++ b/xml/System.Text.Json.Serialization/JsonIgnoreAttribute.xml
@@ -69,9 +69,17 @@ For more information, see [How to serialize and deserialize JSON](/dotnet/standa
         <ReturnType>System.Text.Json.Serialization.JsonIgnoreCondition</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Specifies the condition that must be met before a property will be ignored.</summary>
         <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <remarks>
+          <format type="text/markdown"><![CDATA[
+
+## Remarks
+
+The default value is <xref:System.Text.Json.Serialization.JsonIgnoreCondition.Always>.
+
+          ]]></format>
+        </remarks>
       </Docs>
     </Member>
   </Members>
diff --git a/xml/System.Text.Json.Serialization/JsonIgnoreCondition.xml b/xml/System.Text.Json.Serialization/JsonIgnoreCondition.xml
index 7a0364cd6f8..fc9e9e4a4ea 100644
--- a/xml/System.Text.Json.Serialization/JsonIgnoreCondition.xml
+++ b/xml/System.Text.Json.Serialization/JsonIgnoreCondition.xml
@@ -13,7 +13,7 @@
     <BaseTypeName>System.Enum</BaseTypeName>
   </Base>
   <Docs>
-    <summary>To be added.</summary>
+    <summary>Controls how the <see cref="T:System.Text.Json.Serialization.JsonIgnoreAttribute" /> ignores properties on serialization and deserialization.</summary>
     <remarks>To be added.</remarks>
   </Docs>
   <Members>
@@ -34,7 +34,8 @@
       </ReturnValue>
       <MemberValue>1</MemberValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Property will always be ignored.</summary>
+        <remarks>To be added.</remarks>
       </Docs>
     </Member>
     <Member MemberName="Never">
@@ -54,7 +55,8 @@
       </ReturnValue>
       <MemberValue>0</MemberValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Property will always be serialized and deserialized, regardless of <see cref="P:System.Text.Json.JsonSerializerOptions.IgnoreNullValues" /> configuration.</summary>
+        <remarks>To be added.</remarks>
       </Docs>
     </Member>
     <Member MemberName="WhenWritingDefault">
@@ -74,7 +76,8 @@
       </ReturnValue>
       <MemberValue>2</MemberValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Property will only be ignored if it is <see langword="null" />.</summary>
+        <remarks>To be added.</remarks>
       </Docs>
     </Member>
   </Members>
diff --git a/xml/System.Text.Json.Serialization/JsonIncludeAttribute.xml b/xml/System.Text.Json.Serialization/JsonIncludeAttribute.xml
index 6453977675d..7414aa9b56f 100644
--- a/xml/System.Text.Json.Serialization/JsonIncludeAttribute.xml
+++ b/xml/System.Text.Json.Serialization/JsonIncludeAttribute.xml
@@ -20,8 +20,17 @@
     </Attribute>
   </Attributes>
   <Docs>
-    <summary>To be added.</summary>
-    <remarks>To be added.</remarks>
+    <summary>Indicates that the member should be included for serialization and deserialization.</summary>
+    <remarks>
+      <format type="text/markdown"><![CDATA[
+
+## Remarks
+
+When applied to a property, indicates that non-public getters and setters can be used for serialization and deserialization. Non-public properties are not supported.
+
+          ]]></format>
+    </remarks>
+    <exception cref="T:System.InvalidOperationException">The attribute is applied to a non-public property.</exception>
   </Docs>
   <Members>
     <Member MemberName=".ctor">
@@ -37,7 +46,7 @@
       </AssemblyInfo>
       <Parameters />
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Initializes a new instance of <see cref="T:System.Text.Json.Serialization.JsonIncludeAttribute" />.</summary>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>
diff --git a/xml/System.Text.Json/JsonElement+ArrayEnumerator.xml b/xml/System.Text.Json/JsonElement+ArrayEnumerator.xml
index 1d75d42e6a3..5fcd1eb3d5d 100644
--- a/xml/System.Text.Json/JsonElement+ArrayEnumerator.xml
+++ b/xml/System.Text.Json/JsonElement+ArrayEnumerator.xml
@@ -260,7 +260,15 @@ This member is an explicit interface member implementation. It can be used only
       <Docs>
         <summary>Gets the element in the collection at the current position of the enumerator.</summary>
         <value>The element in the collection at the current position of the enumerator.</value>
-        <remarks>To be added.</remarks>
+        <remarks>
+          <format type="text/markdown"><![CDATA[
+
+## Remarks
+
+This member is an explicit interface member implementation. It can be used only when the <xref:System.Text.Json.JsonElement.ArrayEnumerator> instance is cast to an <xref:System.Collections.IEnumerator> interface.
+
+          ]]></format>
+        </remarks>
       </Docs>
     </Member>
   </Members>
diff --git a/xml/System.Text.Json/JsonElement+ObjectEnumerator.xml b/xml/System.Text.Json/JsonElement+ObjectEnumerator.xml
index 37339c9d073..6c1b31e8bea 100644
--- a/xml/System.Text.Json/JsonElement+ObjectEnumerator.xml
+++ b/xml/System.Text.Json/JsonElement+ObjectEnumerator.xml
@@ -264,7 +264,15 @@ This member is an explicit interface member implementation. It can be used only
       <Docs>
         <summary>Gets the element in the collection at the current position of the enumerator.</summary>
         <value>The element in the collection at the current position of the enumerator.</value>
-        <remarks>To be added.</remarks>
+        <remarks>
+          <format type="text/markdown"><![CDATA[
+
+## Remarks
+
+This member is an explicit interface member implementation. It can be used only when the <xref:System.Text.Json.JsonElement.ObjectEnumerator> instance is cast to an <xref:System.Collections.IEnumerator> interface.
+
+          ]]></format>
+        </remarks>
       </Docs>
     </Member>
   </Members>
diff --git a/xml/System.Text.Json/JsonSerializer.xml b/xml/System.Text.Json/JsonSerializer.xml
index 1ddb10a1418..2fbcbebe50d 100644
--- a/xml/System.Text.Json/JsonSerializer.xml
+++ b/xml/System.Text.Json/JsonSerializer.xml
@@ -482,6 +482,8 @@ For more information, see [How to serialize and deserialize JSON](/dotnet/standa
 
 There is remaining data in the stream.</exception>
         <exception cref="T:System.NotSupportedException">There is no compatible <see cref="System.Text.Json.Serialization.JsonConverter" /> for <typeparamref name="TValue" /> or its serializable members.</exception>
+        <exception cref="T:System.ArgumentNullException">
+          <paramref name="utf8Json" />is <see langword="null" />.</exception>
       </Docs>
     </Member>
     <Member MemberName="Serialize">
diff --git a/xml/System.Text.Json/JsonSerializerOptions.xml b/xml/System.Text.Json/JsonSerializerOptions.xml
index 2919ad0a2ac..60602877039 100644
--- a/xml/System.Text.Json/JsonSerializerOptions.xml
+++ b/xml/System.Text.Json/JsonSerializerOptions.xml
@@ -84,9 +84,11 @@ For more information, see [How to serialize and deserialize JSON](/dotnet/standa
         <Parameter Name="options" Type="System.Text.Json.JsonSerializerOptions" Index="0" FrameworkAlternate="net-5.0" />
       </Parameters>
       <Docs>
-        <param name="options">To be added.</param>
-        <summary>To be added.</summary>
+        <param name="options">The options instance to copy options from.</param>
+        <summary>Copies the options from a <see cref="T:System.Text.Json.JsonSerializerOptions" /> instance to a new instance.</summary>
         <remarks>To be added.</remarks>
+        <exception cref="T:System.ArgumentNullException">
+          <paramref name="options" /> is <see langword="null" />.</exception>
       </Docs>
     </Member>
     <Member MemberName="AllowTrailingCommas">
@@ -547,9 +549,9 @@ For more information, see [How to serialize and deserialize JSON](/dotnet/standa
         <ReturnType>System.Text.Json.Serialization.ReferenceHandler</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>To be added.</summary>
+        <summary>Configures how object references are handled when reading and writing JSON.</summary>
         <value>To be added.</value>
-        <remarks>To be added.</remarks>
+        <remarks>This option provides a convenient way to deal with circularity in object graphs.</remarks>
       </Docs>
     </Member>
     <Member MemberName="WriteIndented">
diff --git a/xml/System.Text.Json/Utf8JsonReader.xml b/xml/System.Text.Json/Utf8JsonReader.xml
index e253e5087fa..6acc983caa8 100644
--- a/xml/System.Text.Json/Utf8JsonReader.xml
+++ b/xml/System.Text.Json/Utf8JsonReader.xml
@@ -350,7 +350,15 @@ The JSON token value represents a number less than <see cref="F:System.Byte.MinV
         <returns>The byte array that represents the current JSON token value.</returns>
         <remarks>To be added.</remarks>
         <exception cref="T:System.InvalidOperationException">The type of the JSON token is not a <see cref="F:System.Text.Json.JsonTokenType.String" />.</exception>
-        <exception cref="T:System.FormatException">The value is not encoded as Base64 text, so it can't be decoded to bytes.</exception>
+        <exception cref="T:System.FormatException">The value is not encoded as Base64 text, so it can't be decoded to bytes.
+
+-or-
+
+The value contains invalid or more than two padding characters.
+
+-or-
+
+The value is incomplete. That is, the JSON string length is not a multiple of 4.</exception>
         <altmember cref="P:System.Text.Json.Utf8JsonReader.TokenType" />
       </Docs>
     </Member>
@@ -415,7 +423,11 @@ This method only creates a <xref:System.DateTime> representation of JSON strings
         
 -or-
         
-The entire UTF-8 encoded token value cannot be parsed to a <see cref="T:System.DateTime" /> value.</exception>
+The entire UTF-8 encoded token value cannot be parsed to a <see cref="T:System.DateTime" /> value.
+
+-or-
+
+The JSON token value is of an unsupported format.</exception>
         <altmember cref="P:System.Text.Json.Utf8JsonReader.TokenType" />
       </Docs>
     </Member>
@@ -454,7 +466,11 @@ This method only creates a <xref:System.DateTimeOffset> representation of JSON s
 
 -or-
         
-The entire UTF-8 encoded token value cannot be parsed to a <see cref="T:System.DateTimeOffset" /> value.</exception>
+The entire UTF-8 encoded token value cannot be parsed to a <see cref="T:System.DateTimeOffset" /> value.
+
+-or-
+
+The JSON token value is of an unsupported format.</exception>
         <altmember cref="P:System.Text.Json.Utf8JsonReader.TokenType" />
       </Docs>
     </Member>