`check_domain`

19 servers reported a tool by this name when we called them. Names are chosen by whoever wrote the server, so two tools sharing a name do not have to do the same thing. We record what was reported, not what it does.

server	result when we called it	tools
arch-tools-mcp https://arch-tools-mcp.onrender.com/sse	answers-mcp	63
arch-tools-mcp https://arch-tools-mcp.onrender.com/mcp	answers-mcp	63
arch-tools https://archtools.dev/mcp	answers-mcp	63
layero https://mcp.layero.ru/mcp	answers-mcp	27
namemyapp-mcp https://mcp.namemy.app/direct	answers-mcp	13
Qualisend https://app.qualisend.com/api/mcp	answers-mcp	12
instadomain https://instadomain.fly.dev/mcp/	answers-mcp	12
phishunt-mcp https://mcp.phishunt.io/	answers-mcp	11
russia-access https://ruscrape.com/mcp	answers-mcp	9
UCP Checker https://ucpchecker.com/mcp	answers-mcp	8
scan.mx https://api.scan.mx/mcp	answers-mcp	6
steadyfetch https://steadyfetch-production.up.railway.app/mcp	answers-mcp	5
nameintel https://mcp.nameintel.io/mcp	answers-mcp	5
agpc-guild https://guild.tradeuniquecapital.com/mcp	answers-mcp	4
email-validator-api https://api.lazy-mac.com/email-validator/mcp	answers-mcp	4
agentdomainsearch https://agentdomainsearch.com/mcp	answers-mcp	3
domain-search-king https://domainsearchking.com/api/mcp	answers-mcp	3
mailverdict https://api.mailverdict.dev/mcp	answers-mcp	2
domain-rdap https://ads.getlulu.dev/domain/mcp	answers-mcp	1

19 of these answered an MCP handshake on the day we checked. That is not a promise the tool works, only that the server was running and told us the tool existed.