Skip to content English Deutsch Essential Tools for Admins, Engineers and AI Agents Network Tools Email Security Browser-based admintoolkit.io brings together essential browser tools for admins, engineers and AI agents: DNS, mail security, TLS, HTTP headers, public IP checks, CIDR, EDID, and agent-readable web metadata such as robots.txt, llms.txt, A2A Agent Cards, and WebMCP tool definitions. The tools are built for traceable diagnostics with local parsing where possible, explicit live lookups, and WebMCP support for AI agents. AI Crawler robots.txt Checker Check RFC 9309 robots.txt matching for documented or custom crawler product tokens with merged groups, transport evidence, and registry provenance. Web / SEO llms.txt Validator Validate the required initial H1, optional summary and project details, and any H2 resource lists with link titles, URLs, optional descriptions, findings, and source-line evidence. Web / SEO A2A Agent Card Validator Validate A2A Agent Card discovery JSON, skills, interfaces, capabilities, and deployment metadata. Agentic Web WebMCP Tool Validator Inspect WebMCP declarative and imperative static source without executing JavaScript; runtime tools require actual browser observation. Agentic Web MX Record Check Query MX records through DNS-over-HTTPS, sort priorities, resolve first hosts, and spot Null MX or CNAME problems. Email Security SPF/DMARC/DKIM Checker Parse SPF, DMARC, and DKIM TXT records, highlight policy issues, and run DNS lookup only when needed. Email Security Email Message Header Analyzer Parse full message headers locally, preserve raw Received order, and classify recorded Authentication-Results without claiming cryptographic or reverse-DNS verification. Email Security ARC Chain Validator Check ARC instance structure, continuity, and recorded cv state without claiming cryptographic validation or sealer trust. Email Security BIMI Checker/Generator Check BIMI records, DMARC readiness, logo and certificate URLs, and generate a