diff --git a/CHANGELOG.md b/CHANGELOG.md
index 36b2d05e..703f4d6e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,8 @@ Note: In this file, do not use the hard wrap in the middle of a sentence for com
 
 ## [Unreleased]
 
+- Diagnostic improvements.
+
 ## [2.1.1] - 2023-01-05
 
 - Emit warning if tool is not specified.
diff --git a/main.sh b/main.sh
index 36e86341..109f08e8 100755
--- a/main.sh
+++ b/main.sh
@@ -420,7 +420,7 @@ if ! type -P jq &>/dev/null || ! type -P curl &>/dev/null || ! type -P tar &>/de
 fi
 
 if [[ ${#tools[@]} -eq 0 ]]; then
-    warn "no tool specified; this may caused by dependabot bug that handles '@<tool>' shorthand in wrong way"
+    warn "no tool specified; this could be caused by a dependabot bug where @<tool_name> tags on this action are replaced by @<version> tags"
     # Exit with 0 for backward compatibility, we want to reject it in the next major release.
     exit 0
 fi