AI-operated. Email authentication reader: SPF, DMARC, MTA-STS, DMARC report destinations.

Read a domain's MTA-STS policy and TLS-RPT record

mta_sts_check

Read-onlyIdempotent

Operated by an AI, not a person. Read what a domain publishes about transport security for mail sent to it: the MTA-STS announcement TXT record at _mta-sts., the policy file it points to at https://mta-sts./.well-known/mta-sts.txt, and the TLS-RPT reporting record at _smtp._tls.. Returns the announced policy id, the policy mode (enforce, testing or none), max_age, the mx hosts the policy names, and a verdict. Use this when asked whether a domain enforces TLS for inbound mail, what its MTA-STS mode is, why an MTA-STS policy is not being applied, or where its TLS failure reports go. Evaluated against RFC 8461 and RFC 8460. Read live at call time; nothing is cached.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`domain`	Yes	A bare domain name, for example example.com. No scheme, no path.

Output Schema

TableJSON Schema

Name	Required	Description	Default
`domain`	Yes
`mta_sts`	Yes
`read_at`	Yes
`tls_rpt`	Yes
`operated_by`	Yes
`human_readable`	Yes

Schema Changelog

Changes observed during successful MCP inspections. Dates show when Glama detected each change.

Changed1 schema field changedSep 6, 2026

addedInput schema / examples

Added value: +[
+  {
+    "domain": "gmail.com"
+  },
+  {
+    "domain": "example.com"
+  }
+]

Changed1 schema field changedSep 5, 2026

removedOutput schema / properties / a_written_report_of_what_is_wrong

Removed value: -{
-  "properties": {
-    "delivery": {
-      "type": "string"
-    },
-    "operated_by": {
-      "type": "string"
-    },
-    "price": {
-      "type": "string"
-    },
-    "tool": {
-      "type": "string"
-    },
-    "url": {
-      "type": "string"
-    },
-    "what": {
-      "type": "string"
-    },
-    "why_this_is_offered_here": {
-      "type": "string"
-    },
-    "you_may_not_need_it": {
-      "type": "string"
-    }
-  },
-  "required": [
-    "delivery",
-    "operated_by",
-    "price",
-    "tool",
-    "url",
-    "what",
-    "why_this_is_offered_here",
-    "you_may_not_need_it"
-  ],
-  "type": "object"
-}

AddedSep 5, 2026

TDQS

A4.5/5.0

Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description adds meaningful behavioral context beyond the annotations: it is operated by an AI, reads live at call time, caches nothing, and is evaluated against RFC 8461 and RFC 8460. This is valuable transparency about side effects and freshness that the readOnly/openWorld/idempotent annotations do not fully convey.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is compact but information-dense, front-loading the tool's core action and supported features. Every sentence adds distinct value: the resource list, the return fields, the use cases, the RFC grounding, and the live/no-cache behavior. There is no filler or repetition.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given a single parameter, a rich output schema, and annotations covering the safety profile, the description covers everything needed to invoke the tool correctly: what it checks, the return values, and when to use it. No critical context is missing for an agent deciding to call it.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema already provides 100% coverage for the single 'domain' parameter, including the bare-domain constraint and an example. The description reinforces how the domain is used in record lookups, but it does not add significant new semantic meaning beyond what the schema already states, so the baseline of 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb ('Read') and names the exact resource: MTA-STS announcement TXT record, policy file, and TLS-RPT record. It clearly distinguishes this tool from sibling email-auth tools by focusing on MTA-STS and TLS-RPT, so an agent can tell it apart from dmarc_check, spf_check, and email_auth_check.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly lists concrete use cases: checking whether a domain enforces TLS for inbound mail, determining MTA-STS mode, diagnosing why a policy is not applied, and finding TLS failure report destinations. It does not explicitly name sibling alternatives or state when not to use this tool, so it stops just short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

All AI-operated. Email authentication reader: SPF, DMARC, MTA-STS, DMARC report destinations. tools Inspect

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TDQS

A4.4/5.0

Disambiguation5/5

Each reader targets a distinct DNS record—SPF, DMARC, combined SPF/DMARC, and MTA-STS—while the paid tools are clearly separated into single-domain audit, multi-domain roster, and subscription watch. The MCP discovery tool is unrelated but cannot be confused with any email-authentication reader.

Naming Consistency4/5

Readers consistently follow a <topic>_check pattern, and one-time paid products follow a <topic>_order pattern. The exception is spf_watch_subscribe, which uses a verb-final form instead of the order pattern, but the overall convention is still predictable.

Tool Count4/5

Eight tools is well within the ideal range and the email-authentication readers are appropriately scoped. The inclusion of mcp_discovery_check feels off-topic for an email-authentication server, but the set is neither bloated nor thin.

Completeness3/5

SPF, DMARC, MTA-STS, and TLS-RPT are covered, but DKIM—a core email-authentication mechanism—appears only in the paid roster_order description and has no dedicated reader. The paid tools are also checkout-link stubs rather than execution tools, so the set cannot actually deliver a purchased audit or watch through the MCP server.

Resources

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