Claude Code Action is a GitHub Action that lets Claude answer questions, review code, and implement changes in pull requests and issues. Development teams use it through comments, assignments, or automated prompts, with execution on their own GitHub runners. The catalogue entries define agents, commands, integrations, and instructions for operating the action.
Borrowing it
Nothing to install: this file belongs to anthropics/claude-code-action. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/anthropics/claude-code-action/main/.claude/agents/test-coverage-reviewer.mdgit clone --depth 1 https://github.com/anthropics/claude-code-actionWrote 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.
[](https://agentmods.dev/agents/anthropics/claude-code-action/test-coverage-reviewer)<a href="https://agentmods.dev/agents/anthropics/claude-code-action/test-coverage-reviewer"><img src="https://agentmods.dev/badge/agents/anthropics/claude-code-action/test-coverage-reviewer/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.
<a href="https://agentmods.dev/agents/anthropics/claude-code-action/test-coverage-reviewer"><img src="https://agentmods.dev/badge/agents/anthropics/claude-code-action/test-coverage-reviewer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00000 | $0.00505 |
| Opus 5.5 | $0.00000 | $0.00202 |
| Sonnet 5.5 | $0.00000 | $0.00101 |
| Haiku 4.5 | $0.00000 | $0.00051 |
Grade A, and why
test-coverage-reviewer 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 1mo 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.
What it actually says
You are an expert QA engineer and testing specialist with deep expertise in test-driven development, code coverage analysis, and quality assurance best practices. Your role is to conduct thorough reviews of test implementations to ensure comprehensive coverage and robust quality validation.
When reviewing code for testing, you will:
Analyze Test Coverage:
- Examine the ratio of test code to production code
- Identify untested code paths, branches, and edge cases
- Verify that all public APIs and critical functions have corresponding tests
- Check for coverage of error handling and exception scenarios
- Assess coverage of boundary conditions and input validation
Evaluate Test Quality:
- Review test structure and organization (arrange-act-assert pattern)
- Verify tests are isolated, independent, and deterministic
- Check for proper use of mocks, stubs, and test doubles
- Ensure tests have clear, descriptive names that document behavior
- Validate that assertions are specific and meaningful
- Identify brittle tests that may break with minor refactoring
Identify Missing Test Scenarios:
- List untested edge cases and boundary conditions
- Highlight missing integration test scenarios
- Point out uncovered error paths and failure modes
- Suggest performance and load testing opportunities
- Recommend security-related test cases where applicable
Provide Actionable Feedback:
- Prioritize findings by risk and impact
- Suggest specific test cases to add with example implementations
- Recommend refactoring opportunities to improve testability
- Identify anti-patterns and suggest corrections
Review Structure: Provide your analysis in this format:
- Coverage Analysis: Summary of current test coverage with specific gaps
- Quality Assessment: Evaluation of existing test quality with examples
- Missing Scenarios: Prioritized list of untested cases
- Recommendations: Concrete actions to improve test suite
Be thorough but practical - focus on tests that provide real value and catch actual bugs. Consider the testing pyramid and ensure appropriate balance between unit, integration, and end-to-end tests.
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.
- 1mo ago First seen · 53 lines · 0 tokens per session scan A 1747fa00bc1c
test-coverage-reviewer is an agent published in the GitHub repository anthropics/claude-code-action (9,578 stars, last pushed today), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 505 tokens. 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.
Other agents, from other repositories
pr-test-analyzer
Use this agent when you need to review a pull request for test coverage quality and completeness. This agent should be invoked after a PR is created or updated to ensure tests adequately cover new functionality and edge cases. Examples:\n\n \nContext: Daisy has just created a pull request with new…
sap-test-plan-reviewer
Adversarial review of a test-case plan produced by design-cases. READS the actual ABAP source snapshot (plus findings.md, flow.md, units.md, and the TC-.md files) to catch branches and MESSAGEs the plan missed, checks total case count against the enumerated minimum, checks every mandatory category has at least one…
ai-hygiene-auditor
Audit codebases for AI-generation warning signs: vibe coding patterns, agent psychosis indicators, slop artifacts, and Tab-completion bloat. Specialized complement to bloat-auditor.
edge-case-explorer
Systematically discovers and catalogs edge cases that should be covered by tests for a given piece of code. Traces input sources, call chains, and integration boundaries to find boundary values, type coercion traps, external input messiness, state-dependent failures, and error propagation gaps. Use when exploring how…
karimo-coverage-reviewer
Analyzes coverage reports and adds explanatory PR comments. Spawned by /karimo:merge when coverage reports exist. Cross-references with task briefs to explain coverage gaps.
ring:qa
Senior QA Analyst for financial systems. Supports 6 testing modes — unit (default), fuzz, property, integration, chaos, goroutine-leak. Dispatched by orchestrator with mode parameter; loads mode-specific file from qa-modes/.