diff --git a/schema/metaschema/sarif-module.xml b/schema/metaschema/sarif-module.xml
index 1c94b0ad..450ca183 100644
--- a/schema/metaschema/sarif-module.xml
+++ b/schema/metaschema/sarif-module.xml
@@ -83,12 +83,36 @@
                 <formal-name>Reporting Descriptor Name</formal-name>
                 <description>A report identifier that is understandable to an end user.</description>
             </define-field>
+            <assembly ref="multiformatMessageString" min-occurs="0">
+                <formal-name>Short Description</formal-name>
+                <description>A concise description of the report. Should be a single sentence that is understandable when visible space is limited to a single line of text.</description>
+                <use-name>shortDescription</use-name>
+            </assembly>
+            <assembly ref="multiformatMessageString" min-occurs="0">
+                <formal-name>Full Description</formal-name>
+                <description>A description of the report. Should, as far as possible, provide details sufficient to enable resolution of any problem indicated by the result.</description>
+                <use-name>fullDescription</use-name>
+            </assembly>
             <define-field name="helpUri" as-type="uri" min-occurs="0">
                 <formal-name>Help URI</formal-name>
                 <description>A URI where the primary documentation for the report can be found.</description>
             </define-field>
         </model>
     </define-assembly>
+    <define-assembly name="multiformatMessageString">
+    	<formal-name>Multi-format Message String</formal-name>
+    	<description>A message string or message format string rendered in multiple formats.</description>
+    	<model>
+    	    <define-field name="text" min-occurs="0">
+                <formal-name>Text</formal-name>
+                <description>A plain text message string or format string.</description>
+            </define-field>
+            <define-field name="markdown" min-occurs="0">
+                <formal-name>Markdown</formal-name>
+                <description>A Markdown message string or format string.</description>
+            </define-field>
+        </model>
+    </define-assembly>
     <define-assembly name="tool">
         <formal-name>Tool</formal-name>
         <description>The analysis tool used.</description>