arnesto: Skill for Claude Code

.agents/skills/xp-increase-coverage/SKILL.md

xp-increase-coverage is a skill for Claude Code, Codex from saski/arnesto. It costs 39 tokens per session (186 once invoked), scanned A, original, Unlicense.

A guide for increasing test coverage with small tests focused on important user and system behavior.

In plain words
What is it for?
Use it to analyze coverage, choose high-value missing behavior, add focused tests, and explain the reliability benefit.
Why use it?
It helps focus testing effort on valuable untested paths and the failures most likely to affect production.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents).

This is saski/arnesto's own configuration. It tells Claude Code and Codex how to work on arnesto 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 arnesto configures →

Reuse

Borrowing it

Nothing to install: this file belongs to saski/arnesto. 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/saski/arnesto/main/.agents/skills/xp-increase-coverage/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/saski/arnesto

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 xp-increase-coverage

README.md
[![agentmods](https://agentmods.dev/badge/skills/saski/arnesto/xp-increase-coverage.svg)](https://agentmods.dev/skills/saski/arnesto/xp-increase-coverage)
Your own site
<a href="https://agentmods.dev/skills/saski/arnesto/xp-increase-coverage"><img src="https://agentmods.dev/badge/skills/saski/arnesto/xp-increase-coverage.svg" alt="Measured on agentmods" height="20"></a>
Per session 39 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 186 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original 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 $0.00039 $0.00186
Opus 5 $0.00019 $0.00093
Sonnet 5 $0.00008 $0.00037
Haiku 4.5 $0.00004 $0.00019

Measured 3d ago against content hash 0b243299e459, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

xp-increase-coverage 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 3d 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/xp-increase-coverage/SKILL.md · 19 lines

What it actually says

Senior XP Developer — Increase Test Coverage

Act as a Senior XP Developer with Lean thinking. Work in small steps, aim for simplicity, and improve reliability through meaningful tests.

Task

  1. Run coverage analysis on the code and identify untested, high-value behavior.
  2. Write a focused test that exercises the most relevant untested path, prioritizing production reliability.
    • Test behavior, not implementation.
    • Keep tests small, clear, and intention-revealing.
  3. Briefly explain:
    • Why this untested path matters.
    • Which failure it helps prevent.
    • How it supports simpler, more evolvable code.
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. 3d ago First seen · 19 lines · 39 tokens per session scan A 0b243299e459

Subscribe to this mod's changes

xp-increase-coverage is a skill published in the GitHub repository saski/arnesto (5 stars, last pushed today), licensed Unlicense. It adds 39 tokens to every session and 186 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.