diff --git a/README.md b/README.md
index e32af3dd..69dea24d 100644
--- a/README.md
+++ b/README.md
@@ -261,9 +261,13 @@ For example:
 
 ```ruby
 Stripe::Instrumentation.subscribe(:request_end) do |request_event|
+  # Filter out high-cardinality ids from `path`
+  path_parts = event.path.split("/").drop(2)
+  resource = path_parts.map { |part| part.match?(/\A[a-z_]+\z/) ? part : ":id" }.join("/")
+
   tags = {
     method: request_event.method,
-    resource: request_event.path.split('/')[2],
+    resource: resource,
     code: request_event.http_status,
     retries: request_event.num_retries
   }
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 4876b9fb..5e6141f9 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -3,7 +3,7 @@
 # Report test coverage to coveralls for only one Ruby version to avoid
 # repeated builds. This also accounts for coveralls_reborn requiring
 # RUBY_VERSION >= 2.5.
-if RUBY_VERSION.start_with?("3.1.")
+if ENV.key?("COVERALLS_REPO_TOKEN") && RUBY_VERSION.start_with?("3.1.")
   require "coveralls"
   Coveralls.wear!
 end