diff --git a/Tools.md b/Tools.md
index ed634d4..2526ffd 100644
--- a/Tools.md
+++ b/Tools.md
@@ -52,6 +52,19 @@
 
     This command will generate a SEL_data.txt file.
 
+## The opal-prd tool: ##
+
+    opal-prd is a tool used by the Energy Scale and RAS tests.  It should be
+    installed on the OS of the system under test before running those tests.
+
+    opal-prd may be installed on Ubuntu with:
+    ```
+    apt install opal-prd
+    ```
+    and on RedHat with:
+    ```
+    yum install opal-prd
+    ```
 
 ## Obtain a copy of GitHub issues in CSV format: ##