Post-Quantum Cryptography MCP Server

by scottdhughes

Overview Schema Source Related Servers Discussions Admin

Python

Local

pqc_hybrid_open

Decrypt a hybrid sealed envelope using its ML-KEM-768 and X25519 secret keys to recover the original plaintext.

Instructions

Decrypt a hybrid sealed envelope using both secret keys.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "envelope": "<envelope>"
    },
    "name": "pqc_hybrid_open"
  }
}

Input Schema

Name	Required	Description
`envelope`	Yes	Sealed envelope from pqc_hybrid_seal
`key_store_name`	No	Name of stored hybrid key bundle
`pqc_secret_key`	No	Base64-encoded ML-KEM-768 secret key
`classical_secret_key`	No	Base64-encoded raw 32-byte X25519 secret key

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.10.0Nov 4, 2026

TDQS

C2.9/5.0

Behavior2/5

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

No annotations are provided, so the description carries the full burden and mostly fails it. It does not say what is returned (plaintext bytes vs. a wrapper), whether integrity/authentication is checked during open, what happens on tampering or a wrong key, or whether either key source satisfies the requirement.

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?

A single front-loaded sentence with no filler or redundancy. Its economy is appropriate, though the brevity borders on under-specification rather than true conciseness.

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

Completeness2/5

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

For a security-sensitive decryption tool with no annotations and no output schema, the definition is thin. An agent cannot tell which of the three key-supplying parameters to use together, nor what a successful versus failed open looks like.

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 coverage is 100%, with each parameter individually described, so the baseline is 3. The phrase 'using both secret keys' adds a weak hint that pqc_secret_key and classical_secret_key are jointly required, but it never clarifies that key_store_name is an alternative source, leaving the schema to do that work.

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

Purpose4/5

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

States a specific verb and resource ('Decrypt a hybrid sealed envelope'), which maps cleanly onto the sibling producer pqc_hybrid_seal. However, it does not distinguish itself from pqc_hybrid_auth_open or pqc_hybrid_decap, which an agent could plausibly confuse it with.

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

Usage Guidelines2/5

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

There is no when-to-use guidance, no mention of when to prefer pqc_hybrid_auth_open (authenticated) or pqc_hybrid_decap, and no stated prerequisites or error conditions. The only usage hint is the implicit pairing with pqc_hybrid_seal via the shared 'envelope' term.

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