test-health-check

test-health-check is a skill for Claude Code from ivklgn/ai-kit. It costs 125 tokens per session (2,136 once invoked), scanned A, original, MIT.

A check that tests whether a unit, integration, or end-to-end test really protects the behaviour it claims to test. It probes whether the test reaches the code, detects plausible breaks, checks the right result, and runs reliably.

In plain words
What is it for?
Use it during test development or review to assess reachability, failure sensitivity, correct assertions, and resistance to flakiness or environmental differences.
Why use it?
It can reveal tests that pass while asserting little, even when code coverage looks good. Coverage only shows which code ran, not whether the test would catch a meaningful failure.

Skill for Claude Code

Written for Claude Code: $ARGUMENTS substitution. Also seen: model in frontmatter.

Part of the ai-kit plugin — 22 skills, 15 commands, 30 agents, 1 MCP server shipped together

Good fit Use it during test development or review to assess reachability, failure sensitivity, correct assertions, and resistance to flakiness or environmental differences.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/ivklgn/ai-kit/test-health-check
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 ivklgn/ai-kit --skill test-health-check
Clone the repo
git clone --depth 1 https://github.com/ivklgn/ai-kit

Made for: Claude Code.

Or install ai-kit, the plugin that ships this one along with the rest of its 22 skills, 15 commands, 30 agents, 1 MCP server.

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 test-health-check

README.md
[![agentmods](https://agentmods.dev/badge/skills/ivklgn/ai-kit/test-health-check/github.svg)](https://agentmods.dev/skills/ivklgn/ai-kit/test-health-check)
Your own site
<a href="https://agentmods.dev/skills/ivklgn/ai-kit/test-health-check"><img src="https://agentmods.dev/badge/skills/ivklgn/ai-kit/test-health-check/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 test-health-check

Your own site · 80×15
<a href="https://agentmods.dev/skills/ivklgn/ai-kit/test-health-check"><img src="https://agentmods.dev/badge/skills/ivklgn/ai-kit/test-health-check.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 125 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,136 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. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium Excessive Agency · line 4
    Skill selects an external model or provider that may use a different account or billing plan than the operator expects. Undisclosed model switches can cause unexpected cost or quota consumption.
    Fix: Remove the model/provider override or disclose it prominently and require explicit operator approval before invoking an external coding CLI or billed model.
How audits are shown
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 $0.00125 $0.02136
Opus 5 $0.00063 $0.01068
Sonnet 5 $0.00025 $0.00427
Haiku 4.5 $0.00013 $0.00214

Measured 6d ago against content hash e05740930dcb, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

test-health-check 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.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/worktree.sh), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

plugins/ai-kit/skills/test-health-check/SKILL.md · 162 lines

How it starts

The opening of the file, as written. The whole thing — 162 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Test Health Check

Produce compact PROOF that a specific test guards its stated contract — by running a few targeted fault probes around the code under test. This is not mutation testing and emits no mutation score. It answers a sharper question for active development: does this test pass on healthy behavior and reliably fail on a plausible, contract-related break?

Why coverage is not enough

A test can execute a line, or even cover an entire method, yet still fail to assert anything meaningful (a "pseudo-tested" method survives having its whole body deleted). And a test that kills mutants can still pin the wrong requirement if its oracle was copied from the implementation. So this skill verifies four independent properties:

  1. Reachability — the test actually exercises the target behavior.
  2. Sensitivity — the test fails under a plausible, contract-related break.
  3. Oracle validity — assertions match the contract/spec/invariant, not the implementation.
  4. Reliability — the result is reproducible and isolated (not flaky / order / environment dependent).

Invocation

$ARGUMENTS may contain a target and flags. The target is a test name, a test/source file, a diff/branch scope, or a described behavior. If no target is given, default to the affected cases of the current branch (see Worktree mode).

Flag Effect
--worktree Run the whole cycle in an isolated git worktree scoped to affected cases. Production tree is never mutated. Strongly preferred.
quick (default) Current test or changed file: baseline → reachability probe → 2 sensitivity probes → restore.
focused Function/class/endpoint/flow: baseline → contract extraction → 3–7 targeted probes → boundary/failure analysis → suggestions.
deep Critical behavior: broader probe set, repeated runs, test-order variation, mock/fixture review, metamorphic checks, boundary verification.
exhaustive Hand off to a real mutation runner for a true score. NOT the primary mode — only for a full module / CI gate / historical comparison.
--fix After diagnosis, propose and verify a minimal test patch (off by default).

Read the full file on GitHub · 162 lines

Files

What ships with it

5 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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 · 162 lines · 125 tokens per session scan A e05740930dcb

Subscribe to this mod's changes

test-health-check is a skill published in the GitHub repository ivklgn/ai-kit (12 stars, last pushed 5d ago), licensed MIT. It adds 125 tokens to every session and 2,136 once invoked, about $0.0006 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 2026-09-04.