/tools/robots does the three things you usually want when debugging crawl behaviour:

1. Fetch https:///robots.txt and show the raw body alongside a parsed view of every User-agent group (Allow / Disallow / Crawl-delay).
2. Test a specific path against a specific User-Agent: tell us the UA (defaults to Googlebot) and the path (defaults to /), and we report Allowed or Blocked plus which Allow: / Disallow: rule decided it. The matcher implements Google's wildcard semantics (* matches any sequence, $ anchors end-of-path) and the longest-match wins.
3. Discover declared sitemaps: any Sitemap: line in the file is collected and rendered as a clickable list — feeds straight into the sitemap validator.

Useful for confirming that a freshly-deployed Disallow: /admin actually blocks /admin/foo but not /administrator, and that the new Sitemap: URL is actually pointing at the right host.