mcp-builder-doctrine

mcp-builder-doctrine is a skill for Claude Code, Codex from ariffazil/AAA. It costs 33 tokens per session (5,913 once invoked), scanned A, original, AGPL-3.0.

A rulebook for building MCP servers, which expose tools to agents through a standard interface. It defines naming, capability declarations, lifecycle updates, and error formats.

In plain words
What is it for?
It is for implementing the structure and behavior of MCP servers.
Why use it?
It gives MCP servers consistent rules for describing tools and reporting their state and failures.

Skill for Claude CodeCodex

Which agent this was written for is unclear — body not stored (licence); the path alone says nothing.

Good fit It is for implementing the structure and behavior of MCP servers.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/ariffazil/aaa/mcp-builder-doctrine
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add ariffazil/AAA --skill mcp-builder-doctrine
Clone the repo
git clone --depth 1 https://github.com/ariffazil/AAA

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for mcp-builder-doctrine

README.md
[![agentmods](https://agentmods.dev/badge/skills/ariffazil/aaa/mcp-builder-doctrine/github.svg)](https://agentmods.dev/skills/ariffazil/aaa/mcp-builder-doctrine)
Your own site
<a href="https://agentmods.dev/skills/ariffazil/aaa/mcp-builder-doctrine"><img src="https://agentmods.dev/badge/skills/ariffazil/aaa/mcp-builder-doctrine/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for mcp-builder-doctrine

Your own site · 80×15
<a href="https://agentmods.dev/skills/ariffazil/aaa/mcp-builder-doctrine"><img src="https://agentmods.dev/badge/skills/ariffazil/aaa/mcp-builder-doctrine.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 33 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,913 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin unknown No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00033 $0.05913
Opus 5 $0.00016 $0.02957
Sonnet 5 $0.00007 $0.01183
Haiku 4.5 $0.00003 $0.00591

Measured 6d ago against content hash af8bb8426df0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

mcp-builder-doctrine scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 6d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

archive/2026-07-25/AAA/skills/ARCHIVE/mcp-builder-doctrine/SKILL.md · 566 lines

The source is not reproduced here

Licensed AGPL-3.0

The repository is licensed AGPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 6d ago First seen · 566 lines · 33 tokens per session scan A af8bb8426df0

Subscribe to this mod's changes

mcp-builder-doctrine is a skill published in the GitHub repository ariffazil/AAA (2 stars, last pushed today), licensed AGPL-3.0. It adds 33 tokens to every session and 5,913 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.