Dechonet MCP

HTTP Security Headers Audit

http_security

Read-onlyIdempotent

Probe a URL's redirect chain and grade its HTTP security headers A+ to F, flagging missing headers and info leaks like server-version disclosure.

Instructions

Follow a URL's HTTP redirect chain and audit response security headers (CSP, HSTS, X-Frame-Options, COOP, CORP, COEP, Permissions-Policy), grading A+ to F on the six core headers (CSP, HSTS, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, Permissions-Policy; COOP/CORP/COEP are reported but not graded) and flagging information leaks such as server-version disclosure. Use this for HTTP-layer/header posture. Use ssl_check instead for certificate or TLS-handshake issues, or security_scan for a full domain report. Read-only (an HTTP GET-style probe that sends no payload); requires no API key; rate-limited. Returns a text report: grade, header findings, redirect trace, issues, and actions.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`url`	Yes	Full URL including scheme (e.g., 'https://example.com/path'). If the scheme is omitted, https:// is assumed. Redirects are followed starting from this URL.

Output Schema

TableJSON Schema

Name	Required	Description
`kpis`	No	Key metrics as label/value pairs
`grade`	No	Letter grade (A+ to F) when the tool grades the target
`score`	No	0-100 score when the tool scores the target
`issues`	No	Detected problems, severity-rated
`status`	Yes	Overall verdict, e.g. 'good' \| 'warning' \| 'bad' \| 'info' \| 'unknown'
`actions`	No	Recommended next actions, most important first
`summary`	No	One-paragraph interpretation of the result
`receipts`	No	Signed observation receipts behind this result, one per lookup: when, from where and under which rules version DechoNet observed it. Each url shows the record and checks its Ed25519 signature.
`reportUrl`	Yes	Human-facing interactive report for this exact lookup on dechonet.com
`observation`	No	How much was actually observed and when. A partial observation means some checks did not answer: missing parts are not verified, never clean.

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedv1.5.14Oct 15, 2026

addedOutput schema / properties / observation

Added value: +{
+  "additionalProperties": false,
+  "description": "How much was actually observed and when. A partial observation means some checks did not answer: missing parts are not verified, never clean.",
+  "properties": {
+    "ageMinutes": {
+      "type": [
+        "number",
+        "null"
+      ]
+    },
+    "cached": {
+      "type": "boolean"
+    },
+    "observedAt": {
+      "type": [
+        "string",
+        "null"
+      ]
+    },
+    "state": {
+      "enum": [
+        "complete",
+        "partial",
+        "unknown"
+      ],
+      "type": "string"
+    }
+  },
+  "required": [
+    "state",
+    "observedAt",
+    "cached",
+    "ageMinutes"
+  ],
+  "type": "object"
+}

addedOutput schema / properties / receipts

Added value: +{
+  "description": "Signed observation receipts behind this result, one per lookup: when, from where and under which rules version DechoNet observed it. Each url shows the record and checks its Ed25519 signature.",
+  "items": {
+    "additionalProperties": false,
+    "properties": {
+      "id": {
+        "type": "string"
+      },
+      "tool": {
+        "type": "string"
+      },
+      "url": {
+        "type": "string"
+      }
+    },
+    "required": [
+      "tool",
+      "id",
+      "url"
+    ],
+    "type": "object"
+  },
+  "type": "array"
+}

Changed1 schema field changedv1.1.0Sep 8, 2026

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "additionalProperties": false,
+  "properties": {
+    "actions": {
+      "description": "Recommended next actions, most important first",
+      "items": {
+        "type": "string"
+      },
+      "type": "array"
+    },
+    "grade": {
+      "description": "Letter grade (A+ to F) when the tool grades the target",
+      "type": "string"
+    },
+    "issues": {
+      "description": "Detected problems, severity-rated",
+      "items": {
+        "additionalProperties": false,
+        "properties": {
+          "key": {
+            "type": "string"
+          },
+          "severity": {
+            "type": "string"
+          }
+        },
+        "required": [
+          "severity",
+          "key"
+        ],
+        "type": "object"
+      },
+      "type": "array"
+    },
+    "kpis": {
+      "description": "Key metrics as label/value pairs",
+      "items": {
+        "additionalProperties": false,
+        "properties": {
+          "label": {
+            "type": "string"
+          },
+          "value": {
+            "type": "string"
+          }
+        },
+        "required": [
+          "label",
+          "value"
+        ],
+        "type": "object"
+      },
+      "type": "array"
+    },
+    "reportUrl": {
+      "description": "Human-facing interactive report for this exact lookup on dechonet.com",
+      "type": "string"
+    },
+    "score": {
+      "description": "0-100 score when the tool scores the target",
+      "type": "number"
+    },
+    "status": {
+      "description": "Overall verdict, e.g. 'good' | 'warning' | 'bad' | 'info' | 'unknown'",
+      "type": "string"
+    },
+    "summary": {
+      "description": "One-paragraph interpretation of the result",
+      "type": "string"
+    }
+  },
+  "required": [
+    "status",
+    "reportUrl"
+  ],
+  "type": "object"
+}

Changed1 schema field changedv1.0.3Jun 17, 2026

changedInput schema / properties / url / description

Previous value: -"URL to check (e.g., https://example.com)"New value: +"Full URL including scheme (e.g., 'https://example.com/path'). If the scheme is omitted, https:// is assumed. Redirects are followed starting from this URL."

First observedv0.1.0Jun 17, 2026

TDQS

A4.6/5.0

Behavior5/5

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

Beyond the annotations (readOnly, idempotent, non-destructive), the description adds that the probe is HTTP GET-style with no payload, requires no API key, is rate-limited, follows redirects, and discloses what the report contains (grade, findings, redirect trace, issues, actions). These are behavioral facts the annotations cannot convey.

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?

Front-loaded with the core action before the graded-header detail, exclusions, and behavioral notes; each sentence carries substantive information. It is dense but not padded, though the parenthetical header lists are lengthy enough to border on over-specification.

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?

For a read-only one-parameter audit tool with an output schema, the description covers purpose, sibling routing, safety profile, prerequisites, and output shape. An agent has everything needed to select and invoke it correctly.

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?

Schema description coverage is 100% for the single 'url' parameter, and the description adds little beyond it — the redirect-following behavior it mentions is already documented in the schema's url description. Baseline 3 is appropriate when the schema carries parameter semantics.

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?

States a specific verb+resource: follows a URL's HTTP redirect chain and audits response security headers, enumerating exactly which headers are graded (six core) versus reported (COOP/CORP/COEP) and the A+–F grading scale. It explicitly names the closest siblings (ssl_check, security_scan) and the layer it owns, so an agent can distinguish it without opening any schema.

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?

Gives an explicit selection rule: 'Use this for HTTP-layer/header posture', then routes certificate/TLS-handshake concerns to ssl_check and full-domain reporting to security_scan. Both the when-to-use and when-not-to-use conditions are stated, leaving nothing to inference.

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