io.github.daedalus/mcp-cryptography

by daedalus

Overview Schema Source Related Servers Discussions Admin

Python

Remote

hmac_verify

Verify HMAC authentication by checking a hex-encoded HMAC against a key and data using SHA-256 or SHA-512.

Instructions

Verify HMAC.

Args: key: Hex-encoded key. data: String that was signed. hmac: Hex-encoded HMAC to verify. algorithm: Hash algorithm - 'sha256' or 'sha512'.

Returns: True if HMAC is valid.

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": {
      "key": "<key>",
      "data": "<data>",
      "hmac": "<hmac>"
    },
    "name": "hmac_verify"
  }
}

Input Schema

Name	Required	Default
`key`	Yes
`data`	Yes
`hmac`	Yes
`algorithm`	No	sha256

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.1Jul 30, 2026

TDQS

A4.3/5.0

Behavior4/5

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

The description outlines the inputs, algorithm choices, and return value clearly, but lacks additional behavioral context such as error handling or security implications.

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 concise but includes a docstring-style parameter list that could be streamlined; still clear and front-loaded.

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?

Given the tool's simplicity and the presence of an output schema (return value), the description fully covers inputs, algorithm, and behavior, leaving no gaps.

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

Parameters5/5

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

With 0% schema coverage, the description adds essential meaning: specifying hex-encoded key and hmac, the data string, and algorithm options, significantly aiding correct invocation.

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 'Verify HMAC' with a specific verb and resource, distinguishing it from sibling tools like hmac_sign and rsa_verify.

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

Usage Guidelines3/5

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

Usage context is implied but not explicitly stated; no guidance on when to use or when not, and no mention of sibling alternatives.

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