liz-tracker: Skill for Claude Code

.claude/skills/mcp-tool-dev/SKILL.md

mcp-tool-dev is a skill for Claude Code from moodler/liz-tracker. It costs 42 tokens per session (902 once invoked), scanned A, original, GPL-3.0.

A guide for building MCP tools, which let an AI agent interact with external services or project functions through a defined interface.

In plain words
What is it for?
Adding tools to mcp-server.ts or declaring them in a space plugin's mcpTools list.
Why use it?
It helps developers follow the project's expected validation, user handling, and testing patterns when adding such tools.

Skill for Claude Code

Written for Claude Code: installed under .claude/.

This is moodler/liz-tracker's own configuration. It tells Claude Code how to work on liz-tracker 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 liz-tracker configures →

Reuse

Borrowing it

Nothing to install: this file belongs to moodler/liz-tracker. 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/moodler/liz-tracker/main/.claude/skills/mcp-tool-dev/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/moodler/liz-tracker

Made for: Claude Code.

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-tool-dev

README.md
[![agentmods](https://agentmods.dev/badge/skills/moodler/liz-tracker/mcp-tool-dev/github.svg)](https://agentmods.dev/skills/moodler/liz-tracker/mcp-tool-dev)
Your own site
<a href="https://agentmods.dev/skills/moodler/liz-tracker/mcp-tool-dev"><img src="https://agentmods.dev/badge/skills/moodler/liz-tracker/mcp-tool-dev/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-tool-dev

Your own site · 80×15
<a href="https://agentmods.dev/skills/moodler/liz-tracker/mcp-tool-dev"><img src="https://agentmods.dev/badge/skills/moodler/liz-tracker/mcp-tool-dev.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 42 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 902 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 $0.00042 $0.00902
Opus 5.5 $0.00017 $0.00361
Sonnet 5.5 $0.00008 $0.00180
Haiku 4.5 $0.00004 $0.00090

Measured 2mo ago against content hash 017545b12a27, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

mcp-tool-dev 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 2mo 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.

.claude/skills/mcp-tool-dev/SKILL.md · 135 lines

The source is not reproduced here

Licensed GPL-3.0

The repository is licensed GPL-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. 2mo ago First seen · 135 lines · 42 tokens per session scan A 017545b12a27

Subscribe to this mod's changes

mcp-tool-dev is a skill published in the GitHub repository moodler/liz-tracker (11 stars, last pushed 1mo ago), licensed GPL-3.0. It adds 42 tokens to every session and 902 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-08-30.

Related

mcp-tool-dev compared with skills from other repositories

mcp-tool-dev next to 6 skills from other repositories
ModTypeStarsLast pushLicenceScanTokensWorks with
mcp-tool-devmoodler/liz-trackerSkill111mo agoGPL-3.0A42Claude Code
imagegenopenai/codexSkill133kyesterdayApache-2.0A113Codex
playwright-climicrosoft/playwrightSkill99kyesterdayApache-2.0A19Claude Code
local-ai-agentsmicrosoft/ai-agents-for-beginnersSkill79k4d agoMITA200Claude Code, Codex
systematic-debuggingobra/superpowersSkill313k3d agoMITA21Claude Code
next-cache-components-adoptionvercel/next.jsSkill143kyesterdayMITA95Claude Code
next-partial-prefetching-adoptionvercel/next.jsSkill143kyesterdayMITA103Claude Code