How to write a rate limiting rule specifically for the Home Page?

We are an Enterprise customer. So when we write rules for cloudflare, the site’s subdommain.domain.tld/ comes first.

How can we write a rate limiting rule for the home page of any of the sites that we protect within our cloudflare instance? If we try to write a rule using */ it matches much too much. It appears we need to use * to match any of the domains. But then * goes on to match too much of the URL.

For some reason, we have crawlers or robots that fetch the home page “/” hundreds of times per minute, and we’d like to use a rate-limiting rule to block them. Other Managed Rules within Cloudflare do not already do this, and Security or Threat assessment is not blocking them all, either.

Can you help please?