diff --git a/.github/dependabot.yml b/.github/dependabot.yml
index eee84d66a..4f285be44 100644
--- a/.github/dependabot.yml
+++ b/.github/dependabot.yml
@@ -1,3 +1,4 @@
+# Dependabot PRs are auto-tidied by .github/workflows/dependabot-tidy.yml
 version: 2
 updates:
   - package-ecosystem: "github-actions"
diff --git a/.github/workflows/dependabot-tidy.yml b/.github/workflows/dependabot-tidy.yml
index ddbe46e99..49bdbc9f0 100644
--- a/.github/workflows/dependabot-tidy.yml
+++ b/.github/workflows/dependabot-tidy.yml
@@ -1,3 +1,7 @@
+# Dependabot only updates go.mod/go.sum in the root module, but this repo has
+# multiple Go modules (see docs/examples/). This workflow runs `make mod_tidy`
+# on Dependabot PRs to keep all go.sum files in sync, preventing go-check CI
+# failures.
 name: Dependabot Tidy
 
 on: