diff --git a/docs/tooling.md b/docs/tooling.md
index 537233eba..067a2323e 100644
--- a/docs/tooling.md
+++ b/docs/tooling.md
@@ -297,6 +297,8 @@ We can also search for changes in specific records by their keys.  On each page
 
 ![History Lookup](img/history-lookup.png)
 
+Search for _exact matches_ using composite key is also supported. When search for a composite key, different fields need to be separated by colons.
+
 Clicking on individual records will bring us back to the object diff view page to see what was changed.