Domain Health
REMOTE · MCP.MODERNMUSTARDSEED.COM
Domain checks: SPF, DKIM, DMARC, BIMI, MTA-STS, SSL/TLS and HTTP security headers.
Available components
Last scanned (16 hours ago)
Scores higher than 74% of remote servers
Reachable. Last reached 22 Oct 2026.
Category Security
How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. How we score → Why this is hard to score →
Endpoint Security80
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- No authorisation is required to call this server. Every tool declares its destructiveHint and none is destructive, so open access doesn't expose one. See how to fix → View diagnostics → Partial
- HTTPS is enforced; there's no plaintext access path. View diagnostics → Pass
- The HSTS (Strict-Transport-Security) header is present. View diagnostics → Pass
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
Transport & Reachability100
- Verified streamable-http transport via a live MCP handshake. View diagnostics → Pass
Schema Quality & AI Usability66
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 1116 tokens (~223/item across 5 items; 5 tools + 0 resources), over budget; trim descriptions and params. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management33
- Stability observed for 10 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- We read all 5 captured tool definition(s), and no name or description among them implies an irreversible operation.Pass
- An AI judge read all 6 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a current MCP spec version (2026-07-28).Pass
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 22 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 30 to 33. That category is still filling its 30-day observation window: 9 days of observed history at the previous scan, 10 at this one. The score rises as the window fills, whether or not the server changes.
- 20 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 23 to 27. That category is still filling its 30-day observation window: 7 days of observed history at the previous scan, 8 at this one. The score rises as the window fills, whether or not the server changes.
- 18 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 17 to 20. That category is still filling its 30-day observation window: 5 days of observed history at the previous scan, 6 at this one. The score rises as the window fills, whether or not the server changes.
- 16 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 10 to 13. That category is still filling its 30-day observation window: 3 days of observed history at the previous scan, 4 at this one. The score rises as the window fills, whether or not the server changes.
- 14 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 3 to 7. That category is still filling its 30-day observation window: 1 days of observed history at the previous scan, 2 at this one. The score rises as the window fills, whether or not the server changes.
- 13 Oct 26 0
- Stability: unverified → 0.03 ▲ functional
- 12 Oct 26 72
First indexed and scored.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 22 Oct 2026 · Probed https://mcp.modernmustardseed.com/domain-health
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=mcp.modernmustardseed.com | CN=YR2,O=Let's Encrypt,C=US | 11 Oct 2026 | 9 Jan 2027 | RSA 2048 | SHA256-RSA | 5037aab1b1b95f22d0713db17fad3a7354f |
| SANs: mcp.modernmustardseed.com | ||||||
| CN=YR2,O=Let's Encrypt,C=US (CA) | CN=Root YR,O=ISRG,C=US | 3 Sept 2025 | 2 Sept 2028 | RSA 2048 | SHA256-RSA | 4ebd24947e24d394802d84a52fd5b319 |
| CN=Root YR,O=ISRG,C=US (CA) | CN=ISRG Root X1,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | RSA 4096 | SHA256-RSA | f24b6d17f9d9ad7cb1c9fea78782699f |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of mcp.modernmustardseed.com. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| com. | present | 19718 | 13 | Verified |
| modernmustardseed.com. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication No authorisation required
The endpoint answered without asking for a token. Anyone who knows the URL can reach it.
| Result | No authorisation required |
|---|---|
| HTTP status | 200 |
| Header | Value |
|---|---|
| strict-transport-security | max-age=63072000 |
| x-content-type-options | nosniff |
| x-frame-options | SAMEORIGIN |
| referrer-policy | strict-origin-when-cross-origin |
| permissions-policy | camera=(), microphone=(), geolocation=() |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://mcp.modernmustardseed.com/domain-health | Verified | 200 | |
| http (plaintext) | http://mcp.modernmustardseed.com/domain-health | HTTPS enforced | 308 | https://mcp.modernmustardseed.com/domain-health |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
check_domain_registration Check domain registration ~175
Read a domain's public registration record from its registry over RDAP (no WHOIS scraping): registrar, creation, expiry and last-change dates, status locks such as clientTransferProhibited, danger states such as redemption period or hold, and nameservers. Also compares the registry's nameservers with the live zone and checks DNSSEC. Subdomains are checked as their registered domain. Some country-code registries do not publish RDAP; the tool says so.
| Name | Type | Req | Description |
|---|---|---|---|
| detail | string | – | "summary" (default) lists only findings that need action; "full" also lists every passing check. |
| domain | string | yes | The domain to check, such as example.com. A website address (https://www.example.com/page) or an email address (jo@example.com) also works; the domain is taken from it. |
No output schema declared.
No examples provided.
check_email_auth Check email authentication ~251
Explain in plain words whether email from a domain will reach the inbox and whether others can forge it. Checks MX, SPF with every include expanded and counted against the 10-lookup limit, DMARC policy, alignment and report permissions, DKIM keys at about 40 common selectors plus any you name (with key size), BIMI, MTA-STS and TLS-RPT, and the DNS rules Google, Yahoo and Microsoft set for bulk senders. Every finding has a severity, a one-sentence fix and the RFC or provider document behind it. Reads public DNS only.
| Name | Type | Req | Description |
|---|---|---|---|
| detail | string | – | "summary" (default) lists only findings that need action; "full" also lists every passing check. |
| dkim_selectors | array | – | Extra DKIM selectors to check, such as the s= value from a DKIM-Signature header (for example "s1" or "selector1"). About 40 common selectors are always checked. |
| domain | string | yes | The domain to check, such as example.com. A website address (https://www.example.com/page) or an email address (jo@example.com) also works; the domain is taken from it. |
No output schema declared.
No examples provided.
check_security_headers Check security headers ~180
Read the HTTP security headers a domain's homepage sends, as a browser receives them, and grade each: Strict-Transport-Security, Content-Security-Policy, clickjacking protection (X-Frame-Options or CSP frame-ancestors), X-Content-Type-Options, Referrer-Policy and Permissions-Policy, plus whether http:// redirects to https://, cookie flags, and software version disclosure. Only public web servers on ports 80 and 443 are contacted.
| Name | Type | Req | Description |
|---|---|---|---|
| detail | string | – | "summary" (default) lists only findings that need action; "full" also lists every passing check. |
| domain | string | yes | The domain to check, such as example.com. A website address (https://www.example.com/page) or an email address (jo@example.com) also works; the domain is taken from it. |
No output schema declared.
No examples provided.
check_ssl Check SSL certificate ~202
Check the HTTPS certificate and TLS setup of a domain on port 443: issuer, expiry date and days left, whether the chain is complete and trusted, whether the certificate matches the name, key type and size, which TLS versions (1.0 to 1.3) the server accepts, and the CAA record that limits who may issue certificates. Checks www as well when given a bare domain. Every finding has a severity, a fix and a citation.
| Name | Type | Req | Description |
|---|---|---|---|
| detail | string | – | "summary" (default) lists only findings that need action; "full" also lists every passing check. |
| domain | string | yes | The domain to check, such as example.com. A website address (https://www.example.com/page) or an email address (jo@example.com) also works; the domain is taken from it. |
| include_www | boolean | – | Also check www.<domain> when a bare domain is given and www exists. Default true. |
No output schema declared.
No examples provided.
full_domain_report Full domain report ~219
Run every Domain Health check on one domain at once (email authentication, SSL and TLS, security headers, registration and DNSSEC) and answer three questions in plain words: will its email land, is its website safe, and is the domain owned well. Returns a score and grade per area, the top fixes across all areas, and every finding with its severity, fix and citation. Takes 5 to 20 seconds.
| Name | Type | Req | Description |
|---|---|---|---|
| detail | string | – | "summary" (default) lists only findings that need action; "full" also lists every passing check. |
| dkim_selectors | array | – | Extra DKIM selectors to check, such as the s= value from a DKIM-Signature header (for example "s1" or "selector1"). About 40 common selectors are always checked. |
| domain | string | yes | The domain to check, such as example.com. A website address (https://www.example.com/page) or an email address (jo@example.com) also works; the domain is taken from it. |
No output schema declared.
No examples provided.
How do I install the Domain Health MCP server?
Domain Health is a hosted endpoint at https://mcp.modernmustardseed.com/domain-health, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
remote · mcp.modernmustardseed.com
claude mcp add --transport http com-modernmustardseed-domain-health 'https://mcp.modernmustardseed.com/domain-health'
What is the Domain Health MCP server?
Domain Health is an MCP server listed in the public MCP registry as com.modernmustardseed/domain-health. Domain checks: SPF, DKIM, DMARC, BIMI, MTA-STS, SSL/TLS and HTTP security headers. This page covers its hosted endpoint (https://mcp.modernmustardseed.com/domain-health).
Is the Domain Health MCP server safe to use?
Domain Health scores 77 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.
What tools does the Domain Health MCP server expose?
Domain Health exposes 5 tools: check_email_auth, check_ssl, check_security_headers, check_domain_registration, full_domain_report. Their descriptions and schemas cost roughly 1,027 tokens of context every time the server is loaded.
Does the Domain Health MCP server require authentication?
No. We connected to Domain Health without credentials and it answered, so anything it exposes is reachable by anyone who knows the address.
Is the Domain Health MCP server still maintained?
Domain Health is still listed as active in the MCP registry. We last reached this channel on 22 October 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.