rusty_apple_mail_mcp: Skill for Claude Code

.agents/skills/mcp-design/SKILL.md

mcp-design is a skill for Claude Code, Codex from like-a-freedom/rusty_apple_mail_mcp. It costs 26 tokens per session (2,317 once invoked), scanned A, original, no licence file.

A design guide for MCP servers, which let an AI agent call external tools through a standard interface. It focuses on tools whose behavior is driven by the user's intent.

In plain words
What is it for?
Use it to create, review, or refactor MCP servers and the tools they expose.
Why use it?
It helps avoid unclear or poorly structured tool interfaces when building or reviewing an MCP server.

Skill for Claude CodeCodex

Which agent this was written for is unclear — body not stored (licence); the path alone says nothing. Also seen: installed under .agents/ (shared by several agents).

This is like-a-freedom/rusty_apple_mail_mcp's own configuration. It tells Claude Code and Codex how to work on rusty_apple_mail_mcp itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything rusty_apple_mail_mcp configures →

Reuse

Borrowing it

Nothing to install: this file belongs to like-a-freedom/rusty_apple_mail_mcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/like-a-freedom/rusty_apple_mail_mcp/main/.agents/skills/mcp-design/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/like-a-freedom/rusty_apple_mail_mcp

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-design

README.md
[![agentmods](https://agentmods.dev/badge/skills/like-a-freedom/rusty_apple_mail_mcp/mcp-design/github.svg)](https://agentmods.dev/skills/like-a-freedom/rusty_apple_mail_mcp/mcp-design)
Your own site
<a href="https://agentmods.dev/skills/like-a-freedom/rusty_apple_mail_mcp/mcp-design"><img src="https://agentmods.dev/badge/skills/like-a-freedom/rusty_apple_mail_mcp/mcp-design/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-design

Your own site · 80×15
<a href="https://agentmods.dev/skills/like-a-freedom/rusty_apple_mail_mcp/mcp-design"><img src="https://agentmods.dev/badge/skills/like-a-freedom/rusty_apple_mail_mcp/mcp-design.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 26 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,317 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 $0.00026 $0.02317
Opus 5 $0.00013 $0.01158
Sonnet 5 $0.00005 $0.00463
Haiku 4.5 $0.00003 $0.00232

Measured 11d ago against content hash f1d85f0d46d8, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

mcp-design 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 11d 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.

.agents/skills/mcp-design/SKILL.md · 270 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

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. 11d ago First seen · 270 lines · 26 tokens per session scan A f1d85f0d46d8

Subscribe to this mod's changes

mcp-design is a skill published in the GitHub repository like-a-freedom/rusty_apple_mail_mcp (9 stars, last pushed 6d ago), with no licence file. It adds 26 tokens to every session and 2,317 once invoked, about $0.0001 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 2026-08-31.

Related

Other skills, from other repositories

sentfromai

Give this agent its own email address — create inboxes, send, reply in-thread, search mail, and manage senders via SentFromAI.

samuelar2/sentfromai-mcp · 33 tokens

opik-diagnose

Surface the Opik traces worth a developer's attention, ranked by signal — Diagnostics issues first, then errors, failed tool calls, latency, regressions, and low online-eval scores. With the Opik MCP connected it lists the project's agentinsightsissue entities, offers to turn Diagnostics on when the project has it…

comet-ml/opik-mcp · 187 tokens

cortex-explore-memory

Explore the memory system's state, find gaps in knowledge, assess coverage, and get diagnostic information. Use when the user asks 'what does my memory look like', 'show me memory stats', 'what am I missing', 'how good is my knowledge', 'memory health', 'show coverage', 'find gaps', 'what topics are weak', or when you…

cdeust/Cortex · 91 tokens

quick-capture

Use this skill to drop a new task into GSD Task Manager from any AI assistant that has the gsd-mcp-server connected.

vscarpenter/gsd-task-manager · 0 tokens

event-staffing-ordering

Order W-2 event staff for US/CA events through TempGuru.

Tempguru-co/tempguru-mcp · 22 tokens

delegacion-local

Regla y catálogo para delegar pasos mecánicos (resumir, clasificar, extraer, boilerplate, mensaje de commit desde un diff, traducir texto o archivo, resumir salida de lint/tests/CI, explicar código, describir una imagen, verificar si el backend local está disponible) a modelos locales vía las tools local del MCP…

ZahiriNatZuke/local-delegate · 137 tokens