Dechonet MCP

SSL Certificate Check

ssl_check

Read-onlyIdempotent

Diagnose certificate and HTTPS handshake problems by checking a host's TLS/SSL expiry, issuer, chain trust, revocation, protocol versions, ciphers, and HSTS, then returning an A+ to F grade.

Instructions

Inspect a host's served TLS/SSL certificate and connection: expiry date, issuer, SAN list, chain integrity, revocation (OCSP, then CRL; unknown when neither answers — not graded unless revoked), TLS version, and HSTS, returning an A+ to F grade weighted by certificate validity (40%), TLS version (25%), chain trust (15%), and HSTS (20%). From Seoul it also lists the protocol versions and cipher suites the server accepts — including SSL 3.0, RC4, 3DES, export, NULL and anonymous suites and the Korean SEED/ARIA ciphers — with TLS compression, secure renegotiation, TLS_FALLBACK_SCSV, DH group size and TLS 1.3 key exchange groups; weak findings cap the grade as SSL Labs does (F, C or B). Use this to diagnose certificate or HTTPS-handshake problems for one host. Use http_security instead to audit response security headers, or security_scan for an all-in-one domain report. Read-only: one full TLS handshake plus opening ClientHello messages whose first answer is read; no application data and no vulnerability probes; requires no API key; rate-limited. Returns a text report: grade, expiry/issuer KPIs, issues, and actions.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`host`	Yes	Hostname to inspect, without scheme (e.g., 'example.com'). The host portion of a pasted URL is also accepted.
`port`	No	TCP port for the TLS handshake. Defaults to 443 (standard HTTPS); set this only for a non-standard HTTPS port such as 8443.

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"
+}

Changed2 schema fields changedv1.0.3Jun 17, 2026

changedInput schema / properties / host / description

Previous value: -"Hostname to check (e.g., example.com)"New value: +"Hostname to inspect, without scheme (e.g., 'example.com'). The host portion of a pasted URL is also accepted."

changedInput schema / properties / port / description

Previous value: -"Port number (default: 443)"New value: +"TCP port for the TLS handshake. Defaults to 443 (standard HTTPS); set this only for a non-standard HTTPS port such as 8443."

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?

Annotations already cover the safety profile (readOnlyHint, destructiveHint=false, idempotentHint, openWorldHint), and the description adds real behavioral context beyond them: one full TLS handshake plus ClientHello messages with only the first answer read, no application data, no vulnerability probes, no API key required, and rate-limited. It also discloses grading weights and how weak findings cap the grade.

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 purpose and routing guidance are front-loaded in the first and middle sentences, and every clause carries information an agent could act on (grading weights, handshake behavior, sibling alternatives). It is dense and long—the cipher-suite and TLS-3.0/SEED/ARIA detail is more than most selection decisions need—but not padding.

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 two-parameter read-only diagnostic with annotations and an output schema present, the description covers everything selection-relevant: scope, safety, limitations, alternatives, and grading logic. Return values are summarized without needing to duplicate the output schema.

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%, so both parameters (host, port) are already fully documented with defaults and format guidance. The description adds no syntax, format, or edge-case meaning beyond the schema, 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 names a specific verb and resource (inspect a host's served TLS/SSL certificate and connection) and enumerates exactly what is examined: expiry, issuer, SAN list, chain integrity, revocation, TLS version, HSTS, plus a letter grade. It also names the sibling tools it is not (http_security, security_scan), so an agent can disambiguate without opening schemas.

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?

Explicit when-to-use ("diagnose certificate or HTTPS-handshake problems for one host") paired with explicit alternatives for adjacent tasks ("Use http_security instead to audit response security headers, or security_scan for an all-in-one domain report"). Routing is unambiguous.

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