OnlineCyberTools MCP (280+ filterable tools)

osint_email_headers

Read-onlyIdempotent

Parse raw email headers from 'Show original' into a structured forensic report showing the delivery path, authentication results (SPF/DKIM/DMARC), and security indicators without querying external servers.

Instructions

Email Header Analyzer. Parse raw email headers (the "Show original" / full source block of a message) into a structured forensic report: the Received hop chain reversed into chronological delivery order, SPF/DKIM/DMARC results extracted from Authentication-Results, sender/subject/date basic info, TLS version and cipher, spam indicators, attachment hints, and an overall summary with recommendations. Use this when you already have the literal header text and want to trace how a message travelled and whether its authentication passed. It does NOT query DNS or contact any server, so it cannot fetch a domain's published policy - use network_spf_record_checker or network_dmarc_record_checker for live DNS record lookups, and osint_domain_age for registration data. Runs locally on the text you provide: read-only, non-destructive, offline, and rate-limited (10 requests/minute for anonymous callers, CAPTCHA above 30/hour). Returns nested analysis objects (basic_info, routing, authentication, security, spam_indicators,

Input Schema

TableJSON Schema

Name	Required	Description	Default
`headers`	Yes	Raw email header text, one "Header-Name: value" per line with leading-whitespace folded continuation lines supported. Header names are matched case-insensitively. Must not be blank. Paste the full headers from "Show original"/"View source".

Output Schema

TableJSON Schema

Name	Required	Description
`success`	No	Whether the headers were parsed successfully.
`analysis`	No	Full parsed analysis. Absent when success is false (error string returned instead).
`error`	No	Error message; present only when success is false (blank input or parser failure).

Schema Changelog

Changes observed during successful MCP inspections.

Changed3 schema fields changedv0.5.1Jun 3, 2026

addedInput schema / additionalProperties
```
Added value: +false
```

addedInput schema / properties / headers / description

Added value: +"Raw email header text, one \"Header-Name: value\" per line with leading-whitespace folded continuation lines supported. Header names are matched case-insensitively. Must not be blank. Paste the full headers from \"Show original\"/\"View source\"."

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "properties": {
+    "analysis": {
+      "description": "Full parsed analysis. Absent when success is false (error string returned instead).",
+      "properties": {
+        "attachments": {
+          "properties": {
+            "boundary": {
+              "description": "MIME multipart boundary, or null.",
+              "type": [
+                "string",
+                "null"
+              ]
+            },
+            "content_type": {
+              "description": "Raw Content-Type value, or null.",
+              "type": [
+                "string",
+                "null"
+              ]
+            },
+            "has_attachments": {
+              "description": "True when Content-Type is multipart.",
+              "type": "boolean"
+            },
+            "parts": {
+              "description": "Reserved; currently always empty.",
+              "items": {
+                "type": "object"
+              },
+              "type": "array"
+            }
+          },
+          "type": "object"
+        },
+        "authentication": {
+          "description": "SPF/DKIM/DMARC results extracted from Authentication-Results header(s).",
+          "properties": {
+            "authentication_results": {
+              "description": "All parsed Authentication-Results entries (each with raw plus any spf/dkim/dmarc).",
+              "items": {
+                "type": "object"
+              },
+              "type": "array"
+            },
+            "dkim": {
+              "description": "DKIM result object {result, details} or null.",
+              "type": [
+                "object",
+                "null"
+              ]
+            },
+            "dmarc": {
+              "description": "DMARC result object {result, details} or null.",
+              "type": [
+                "object",
+                "null"
+              ]
+            },
+            "issues": {
+              "description": "Warnings for any auth method whose result is not pass ({type, message}).",
+              "items": {
+                "type": "object"
+              },
+              "type": "array"
+            },
+            "spf": {
+              "description": "SPF result object {result, details} or null if not present.",
+              "type": [
+                "object",
+                "null"
+              ]
+            }
+          },
+          "type": "object"
+        },
+        "basic_info": {
+          "description": "From/To/Subject/Date/Message-ID plus, when parseable, sender_name, sender_email, parsed_date (UTC) and unix timestamp. Missing fields are the string \"Not found\".",
+          "type": "object"
+        },
+        "headers": {
+          "additionalProperties": {
+            "items": {
+              "type": "string"
+            },
+            "type": "array"
+          },
+          "description": "Parsed header map: lowercase header name to array of string values (a header may appear more than once).",
+          "type": "object"
+        },
+        "routing": {
+          "description": "Delivery path from Received headers.",
+          "properties": {
+            "delivery_time": {
+              "description": "Seconds between first and last hop timestamp, or null if not computable.",
+              "type": [
+                "integer",
+                "null"
+              ]
+            },
+            "delivery_time_formatted": {
+              "description": "Human-readable delivery duration (present only when delivery_time is set).",
+              "type": "string"
+            },
+            "path": {
+              "description": "Each Received hop parsed into from/by/with/id/for/timestamp/formatted_date/raw (each null when absent).",
+              "items": {
+                "type": "object"
+              },
+              "type": "array"
+            },
+            "received_headers": {
+              "description": "Raw Received header strings, reversed into chronological (oldest-first) order.",
+              "items": {
+                "type": "string"
+              },
+              "type": "array"
+            },
+            "total_hops": {
+              "description": "Count of Received headers found.",
+              "type": "integer"
+            }
+          },
+          "type": "object"
+        },
+        "security": {
+          "description": "Transport security extracted from Received headers.",
+          "properties": {
+            "cipher_suite": {
+              "description": "Cipher from a (cipher=...) token, or null.",
+              "type": [
+                "string",
+                "null"
+              ]
+            },
+            "recommendations": {
+              "description": "Security recommendations (may be empty).",
+              "items": {
+                "type": "string"
+              },
+              "type": "array"
+            },
+            "security_issues": {
+              "description": "Warnings, e.g. missing Authentication-Results header.",
+              "items": {
+                "type": "object"
+              },
+              "type": "array"
+            },
+            "tls_version": {
+              "description": "TLS version from a (version=...) token, or null.",
+              "type": [
+                "string",
+                "null"
+              ]
+            }
+          },
+          "type": "object"
+        },
+        "spam_indicators": {
+          "properties": {
+            "indicators": {
+              "description": "Heuristic flags ({type, message}), e.g. From/Reply-To mismatch or bulk-mail markers.",
+              "items": {
+                "type": "object"
+              },
+              "type": "array"
+            },
+            "risk_level": {
+              "description": "Spam risk derived from the score.",
+              "enum": [
+                "low",
+                "medium",
+                "high"
+              ],
+              "type": "string"
+            },
+            "score": {
+              "description": "Numeric value parsed from X-Spam-Score (0 if absent/unparseable).",
+              "type": "number"
+            }
+          },
+          "type": "object"
+        },
+        "summary": {
+          "properties": {
+            "authentication_status": {
+              "description": "Overall auth grade from pass ratio.",
+              "enum": [
+                "unknown",
+                "poor",
+                "moderate",
+                "good",
+                "excellent"
+              ],
+              "type": "string"
+            },
+            "recommendations": {
+              "description": "Top-level recommendations (may be empty).",
+              "items": {
+                "type": "string"
+              },
+              "type": "array"
+            },
+            "routing_hops": {
+              "description": "Number of Received hops.",
+              "type": "integer"
+            },
+            "security_level": {
+              "description": "Overall security level (unknown by default).",
+              "type": "string"
+            },
+            "total_headers": {
+              "description": "Total header values parsed.",
+              "type": "integer"
+            }
+          },
+          "type": "object"
+        }
+      },
+      "type": "object"
+    },
+    "error": {
+      "description": "Error message; present only when success is false (blank input or parser failure).",
+      "type": "string"
+    },
+    "success": {
+      "description": "Whether the headers were parsed successfully.",
+      "type": "boolean"
+    }
+  },
+  "type": "object"
+}

First observedv0.1.0May 31, 2026

TDQS

A4.6/5.0

Behavior4/5

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

Annotations already declare readOnlyHint, destructiveHint, idempotentHint, and openWorldHint. The description adds valuable behavioral context: it runs locally, offline, with rate limits (10 req/min, CAPTCHA above 30/hr). This extra detail earns a 4.

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

Conciseness4/5

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

The description is relatively long but well-structured and front-loaded with the core purpose. Each sentence provides meaningful information. While it could be slightly trimmed, the length is justified by the tool's complexity and the need for sibling differentiation.

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?

Despite the tool's complexity, the description covers all critical aspects: input, output, behavior, limitations, and alternatives. The presence of an output schema (mentioned but not shown) reduces the need for describing return values. The description is fully sufficient.

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

Parameters4/5

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

The single parameter has 100% schema coverage. The description adds practical guidance on what to paste ('Show original'/'View source'), which helps the agent understand the expected input format better. This adds value beyond the schema.

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 clearly states the tool parses raw email headers into a structured forensic report, listing specific extracted elements (Received chain, SPF/DKIM/DMARC, etc.). It distinguishes itself from sibling tools by explicitly stating it does not perform DNS lookups and pointing to alternatives.

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

Usage Guidelines5/5

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

The description explicitly states when to use the tool (when you have literal header text) and what it does not do (no DNS queries). It also names specific sibling tools for live DNS lookups and domain registration data, providing clear guidance on alternatives.

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

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