cmcp

by DeveshB-1

Overview Schema Source Related Servers Discussions Admin

Python

Local

Headers/Request Headers

headers_request_headers

Read-only

Retrieve all request headers as JSON from a GET endpoint to inspect exactly which headers your HTTP request sent.

Instructions

A GET request to this endpoint returns the list of all request headers as part of the response JSON. In Postman, sending your own set of headers through the Headers tab will reveal the headers as part of the response.

(Postman request: Headers/Request Headers | GET https://postman-echo.com/headers)

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "headers_request_headers"
  }
}

Input Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Nov 1, 2026

TDQS

B3.2/5.0

Behavior3/5

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so safety is covered. The description's added value is the echo semantics (headers you send are reflected back in the response), which is genuinely useful, but it omits auth requirements, error behavior, and what the response shape looks like.

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

Conciseness3/5

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

The first sentence is front-loaded and useful, but the second is rambling, and the trailing '(Postman request: Headers/Request Headers | GET https://postman-echo.com/headers)' largely restates the name and title rather than adding information. Tightening it would improve the definition.

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

Completeness3/5

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

For a zero-parameter read tool with annotations and no output schema, the description covers the essentials of what it does. Still missing: how it differs from `headers_response_headers`, and what the response actually contains, so an agent could pick the wrong sibling but still call this one correctly.

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

Parameters4/5

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

The tool takes zero parameters, so there are no semantics to document and the schema is the whole contract. A 4 is the appropriate baseline; nothing in the description misleads about inputs.

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?

The description gives a specific verb and resource: a GET returns the list of all request headers in the response JSON. It's clear what the tool does in isolation, but it never distinguishes itself from the sibling `headers_response_headers`, which an agent could easily confuse with this one.

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?

The only usage signal is implicit — sending your own headers via Postman's Headers tab makes them appear in the response, which hints this tool echoes caller-supplied headers. There is no explicit when-to-use, no exclusion, and no pointer to the near-identical `headers_response_headers` sibling.

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