CyberChef MCP Server

cyberchef_describe_operation

Read-onlyIdempotent

Retrieve argument schemas, defaults, and types for one or more CyberChef operations to prepare correct inputs before baking.

Instructions

Full argument schema, defaults and types for one or more operations. This is what you need before calling cyberchef_bake with a new operation.

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": {
      "operations": "<operations>"
    },
    "name": "cyberchef_describe_operation"
  }
}

Input Schema

Name	Required	Description	Default
`operations`	Yes	One operation name, or several, e.g. "AES Encrypt" or ["Gzip", "To Base64"]

Schema Changelog

Changes observed during successful MCP inspections.

First observedv3.6.0Sep 4, 2026

TDQS

A4.2/5.0

Behavior4/5

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

Annotations already establish that this is read-only, idempotent, and non-destructive. The description adds meaningful behavioral context by specifying what information the tool returns (schema, defaults, types) and why it matters for baking operations. This goes beyond simply restating the annotations.

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

Conciseness5/5

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

The description is two concise sentences with no filler. The core value proposition is front-loaded, and the practical usage note immediately follows, making it easy for an agent to parse and act on.

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

Completeness4/5

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

Given the low complexity, high schema coverage, and read-only annotations, the description is largely complete. It states the input, the output content, and the usage context, though it does not mention error behavior for unknown operation names—a minor gap.

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?

The schema already documents the operations parameter with examples and types, so description-level parameter explanation is not critical. The description reinforces that one or more operation names are accepted and that this is for new operations, but it does not add significant semantic detail 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's function: it returns the full argument schema, defaults, and types for one or more operations. It also distinguishes itself from cyberchef_bake by positioning this as a required prerequisite step, making its purpose unambiguous.

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

Usage Guidelines4/5

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

The description explicitly tells the agent when to use this tool: before calling cyberchef_bake with a new operation. It does not enumerate alternatives or exclusions, but the workflow context is clear enough to guide correct usage.

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