Agent skill

Check Coverage

Comprehensive assessment of Unit / Integration / E2E three-layer test coverage, identify gaps and provide actionable recommendations.

MITAuto-check passedTesting & QA

Install Check Coverage

skills CLI

$ npx skills add sd0xdev/sd0x-harness --skill check-coverage -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install sd0xdev/sd0x-harness check-coverage --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/sd0xdev/sd0x-harness.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/check-coverage .claude/skills/check-coverage && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "check-coverage" agent skill from https://github.com/sd0xdev/sd0x-harness/tree/main/skills/check-coverage into .claude/skills/check-coverage/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "check-coverage", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/sd0xdev/sd0x-harness/tree/main/skills/check-coverage

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add sd0xdev/sd0x-harness --skill check-coverage -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install sd0xdev/sd0x-harness check-coverage --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/sd0xdev/sd0x-harness.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/check-coverage .agents/skills/check-coverage && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "check-coverage" agent skill from https://github.com/sd0xdev/sd0x-harness/tree/main/skills/check-coverage into .agents/skills/check-coverage/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "check-coverage", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add sd0xdev/sd0x-harness --skill check-coverage -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install sd0xdev/sd0x-harness check-coverage --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/sd0xdev/sd0x-harness.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/check-coverage .cursor/skills/check-coverage && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "check-coverage" agent skill from https://github.com/sd0xdev/sd0x-harness/tree/main/skills/check-coverage into .cursor/skills/check-coverage/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "check-coverage", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/sd0xdev/sd0x-harness.git --path skills/check-coverage

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add sd0xdev/sd0x-harness --skill check-coverage -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install sd0xdev/sd0x-harness check-coverage --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/sd0xdev/sd0x-harness.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/check-coverage .gemini/skills/check-coverage && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "check-coverage" agent skill from https://github.com/sd0xdev/sd0x-harness/tree/main/skills/check-coverage into .gemini/skills/check-coverage/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "check-coverage", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install sd0xdev/sd0x-harness check-coverage

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add sd0xdev/sd0x-harness --skill check-coverage -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/sd0xdev/sd0x-harness.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/check-coverage .github/skills/check-coverage && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "check-coverage" agent skill from https://github.com/sd0xdev/sd0x-harness/tree/main/skills/check-coverage into .github/skills/check-coverage/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "check-coverage", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add sd0xdev/sd0x-harness --skill check-coverage -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install sd0xdev/sd0x-harness check-coverage --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/sd0xdev/sd0x-harness.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/check-coverage .opencode/skills/check-coverage && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "check-coverage" agent skill from https://github.com/sd0xdev/sd0x-harness/tree/main/skills/check-coverage into .opencode/skills/check-coverage/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "check-coverage", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: check-coverage
GitHub stars: 192
Token cost: ~638 tokens
SKILL.md length: 166 words
Files: 1
Skills in repo: 91
Repo updated: Oct 6, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Comprehensive assessment of Unit / Integration / E2E three-layer test coverage, identify gaps and provide actionable recommendations.

Works in 5 steps: Read Feature Documentation → Identify Related Source Code → Map Test Files → …
Tasks that involve Test coverage
SKILL.md covers Trigger, When NOT to Use, Parent Skill Reference and Agent Dispatch, plus 2 more sections
Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Check Coverage is an agent skill from sd0xdev/sd0x-harness. Comprehensive assessment of Unit / Integration / E2E three-layer test coverage, identify gaps and provide actionable recommendations.

Its SKILL.md is about 640 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Testing & QA, covering Test coverage and End-to-end testing. The repository describes itself as: The harness layer for Claude Code — a reference implementation of harness engineering with hook-enforced dual review, state-machine gates that survive context compaction, and… The licence is MIT.

When your agent uses it

Tasks that involve Test coverage
Tasks that involve End-to-end testing

Example prompts

“/check-coverage”

Requirements

Pre-approved tools (allowed-tools): Read, Grep, Glob, Bash(ls:*), Bash(find:*), Bash(wc:*), Agent

Workflow steps

5 steps, taken from the step headings in SKILL.md.

Read Feature Documentation
Identify Related Source Code
Map Test Files
Analyze Coverage Gaps
Classify and Recommend

What it can do on your machine

Read from SKILL.md and the folder at commit c9a2036. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves these tools, so the agent can use them without asking each time:
- Read
- Grep
- Glob
- Bash(ls:*)
- Bash(find:*)
- Bash(wc:*)
- Agent
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md (its code samples are markdown).
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Check Coverage loads about 638 tokens when it runs. Until then it costs about 37 tokens; SKILL.md has 166 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~37
When it runs · the whole SKILL.md, loaded when a task matches: ~638

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from sd0xdev/sd0x-harness at commit c9a2036, republished under its MIT licence (© sd0xdev). 166 words, ~638 tokens.

Download SKILL.mdSave it as .claude/skills/check-coverage/SKILL.md (or your agent's skills folder).

name: check-coverage
description: Comprehensive assessment of Unit / Integration / E2E three-layer test coverage, identify gaps and provide actionable recommendations.
allowed-tools: Read, Grep, Glob, Bash(ls:*), Bash(find:*), Bash(wc:*), Agent

Test Coverage Analysis

Trigger

Keywords: check coverage, test coverage, coverage analysis, coverage gaps, check-coverage

When NOT to Use

Test sufficiency review via Codex (use /codex-test-review)
Generating tests (use /codex-test-gen)
Running tests (use /verify)

Parent Skill Reference

See @skills/test-review/SKILL.md for Codex-based test review workflow.

Agent Dispatch

Agent({
  description: "Assess three-layer test coverage and identify gaps",
  subagent_type: "coverage-analyst",
  prompt: `Assess Unit / Integration / E2E test coverage for the feature docs at: $ARGUMENTS
Follow the steps defined in this skill.`
})

Task

Step 1: Read Feature Documentation

Read specified feature docs. Extract:

Feature name and objectives
Involved Service / Provider / Entity
Core flows and boundary conditions

Search related source code based on feature documentation. Build source code inventory.

Step 3: Map Test Files

Check whether each source file has corresponding tests (unit, integration, e2e).

Step 4: Analyze Coverage Gaps

For each source file:

Read source: Identify public methods, important branches, error handling
Read tests: Identify covered cases
Compare gaps: missing methods, uncovered branches, untested error scenarios

Severity	Description
🔴 Critical	Core logic, data writes, amount calculations
🟠 Major	Important branches, error handling
🟡 Minor	Edge cases, utility functions
⚪ Nice-to-have	Logging, formatting

Output

markdown

# Test Coverage Analysis Report

## Feature Overview
- Feature name: <from documentation>
- Documentation path: $ARGUMENTS
- Related modules: <list>

## Current Coverage
| Module | Source Path | Test Path | Coverage Status |
|--------|------------|-----------|----------------|

## Coverage Gaps
### 🔴 Critical
### 🟠 Major
### 🟡 Minor

## Recommended New Tests
| Priority | Test Type | Test Case | Target File |
|----------|-----------|-----------|-------------|

## Coverage Summary
| Metric | Status |
|--------|--------|
| Feature coverage | X/Y (Z%) |
| Happy path | ✅/❌ |
| Error path | ✅/❌ |
| Edge cases | ✅/❌ |

Files

Just SKILL.md in skills/check-coverage of sd0xdev/sd0x-harness.

Open the folder on GitHubat commit c9a2036

Compare with similar skills

Check Coverage next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Check Coverage compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Check Coverage this skillsd0xdev/sd0x-harness	192	—	~638	Automated safety check: Pass	MIT	yesterday
Atdd Mutateswingerman/engineer	154	—	~2.7k	Automated safety check: Pass	MIT	14 days ago
E2E Test ThinkerUniClipboard/UniClipboard	1.8k	—	~1.7k	Automated safety check: Pass	AGPL-3.0	today
Check Test Coverageopenshift/oc-mirror	124	—	~853	Automated safety check: Pass	Apache-2.0	yesterday
E2E Test Creatorletehaha/moneymatter	158	—	~2.4k	Automated safety check: Warn	AGPL-3.0	2 days ago
Platform Dsar Policy Manageforcedotcom/sf-skills	1.1k	—	~5.2k	Automated safety check: Pass	Apache-2.0	4 days ago

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Questions about Check Coverage

What does Check Coverage do?

Comprehensive assessment of Unit / Integration / E2E three-layer test coverage, identify gaps and provide actionable recommendations. Check Coverage is an agent skill from sd0xdev/sd0x-harness. Comprehensive assessment of Unit / Integration / E2E three-layer test coverage, identify gaps and provide actionable recommendations.

When should I use Check Coverage?

Check Coverage fits situations like: tasks that involve Test coverage; tasks that involve End-to-end testing.

How do I install Check Coverage in Claude Code?

Run `npx skills add sd0xdev/sd0x-harness --skill check-coverage -a claude-code`. Or copy the skill folder (skills/check-coverage in sd0xdev/sd0x-harness) into .claude/skills/check-coverage in your project. Claude Code loads it when a task matches its description.

How do I install Check Coverage in Codex?

Run `npx skills add sd0xdev/sd0x-harness --skill check-coverage -a codex`. Or copy the skill folder (skills/check-coverage in sd0xdev/sd0x-harness) into .agents/skills/check-coverage in your project. Codex loads it when a task matches its description.

Can I use Check Coverage in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add sd0xdev/sd0x-harness --skill check-coverage -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/check-coverage, .gemini/skills/check-coverage, .github/skills/check-coverage and .opencode/skills/check-coverage in your project.

What does Check Coverage need to run?

SKILL.md names no scripts, command-line tools or credentials: Check Coverage is instructions for the agent only. Its frontmatter pre-approves these tools: Read, Grep, Glob, Bash(ls:*), Bash(find:*), Bash(wc:*), Agent.

Does Check Coverage access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Check Coverage safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Check Coverage use?

Check Coverage is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Check Coverage use?

About 638 tokens (SKILL.md is roughly 2.6k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Check Coverage?

Skills that share tags, products or a category with Check Coverage: Atdd Mutate (swingerman/engineer, 154 stars), E2E Test Thinker (UniClipboard/UniClipboard, 1.8k stars), Check Test Coverage (openshift/oc-mirror, 124 stars) and E2E Test Creator (letehaha/moneymatter, 158 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Check Coverage?

sd0xdev (a GitHub user) maintains it in sd0xdev/sd0x-harness, which has 192 GitHub stars. The repository holds 91 skills in this directory. The repository was last updated on October 6, 2026.

Source: sd0xdev/sd0x-harness on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Check Coverage

Facts

At a glance

What it does

When your agent uses it

Example prompts

Requirements

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Test Coverage Analysis

Trigger

When NOT to Use

Parent Skill Reference

Agent Dispatch

Task

Step 1: Read Feature Documentation

Step 2: Identify Related Source Code

Step 3: Map Test Files

Step 4: Analyze Coverage Gaps

Step 5: Classify and Recommend

Output

Files

Compare with similar skills

Similar skills

More from sd0xdev/sd0x-harness

Related

Questions about Check Coverage