Analyze raw RFC 822 email headers to inspect SPF, DKIM, and DMARC verdicts, trace hop relay timelines, and assign a security grade for authentication auditing.
Deep RFC 822 email header analyzer: inspects SPF, DKIM, DMARC verdicts, hop relay transit timeline, and security grading.
| Name | Required | Description | Default |
|---|---|---|---|
| headers | Yes | Raw RFC 822 email headers string |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations exist, so the description carries the full burden. It does disclose that the operation produces authentication verdicts, a hop transit timeline, and a security grading — useful output-shape context for a pure read-only analysis. However, it never states it is read-only/non-mutating, says nothing about input validation failures (malformed headers), rate limits, or what the grade scale means.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
A single dense sentence, front-loaded with the tool's identity and followed by the analyzed artifacts. No filler, though the colon-list construction is terse to the point of omitting any operational guidance.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a one-parameter analyzer with no output schema and no annotations, the description gives the analytical coverage but not the result shape (field names, grading scale, how hops are reported) or failure behavior. Adequate to know what the tool is for, but thin for knowing what will come back.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100% for the single required parameter 'headers', already documented as 'Raw RFC 822 email headers string'. The description adds no format detail (e.g., whether Received: ordering matters, whether the body must be excluded), so baseline 3 applies.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
States a specific verb (analyze) and resource (RFC 822 email headers) plus the concrete artifacts it inspects: SPF, DKIM, DMARC verdicts, relay hops, and a security grade. It is distinguishable from siblings like check_spam_score or check_dns by scope, though it never names those siblings to draw the contrast explicitly.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
Usage is only implied: the phrase 'raw RFC 822 email headers' signals the input must be full raw headers rather than a parsed summary, but there is no statement of when to prefer this over aliasmail_check_spam_score or aliasmail_check_dns, and no prerequisites or exclusions are given.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.