test-coverage-reviewer

test-coverage-reviewer is an agent for Claude Code from anthropics/claude-code-action. It costs 0 tokens per session (505 once invoked), scanned A, original, MIT.

A testing and code-coverage review agent. Code coverage measures which parts of a program’s code are exercised by tests, while test quality checks whether those tests are reliable and meaningful.

In plain words
What is it for?
Use it after adding features, refactoring code, or completing a module to review test coverage and identify missing scenarios.
Why use it?
It finds untested paths, edge cases, error handling, and brittle tests that ordinary review may miss. It also checks whether tests are isolated, deterministic, and clearly asserted.

Agent for Claude Code

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.

agentmods
npx agentmods add agents/anthropics/claude-code-action/test-coverage-reviewer
Clone the repo
git clone --depth 1 https://github.com/anthropics/claude-code-action

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 test-coverage-reviewer

README.md
[![agentmods](https://agentmods.dev/badge/agents/anthropics/claude-code-action/test-coverage-reviewer.svg)](https://agentmods.dev/agents/anthropics/claude-code-action/test-coverage-reviewer)
Your own site
<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="Measured on agentmods" height="20"></a>
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 505 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 $0.00000 $0.00505
Opus 5 $0.00000 $0.00253
Sonnet 5 $0.00000 $0.00101
Haiku 4.5 $0.00000 $0.00051

Measured 4d ago against content hash 1747fa00bc1c, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

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 4d 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/agents/test-coverage-reviewer.md · 53 lines

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.

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. 4d ago First seen · 53 lines · 0 tokens per session scan A 1747fa00bc1c

Subscribe to this mod's changes

test-coverage-reviewer is an agent published in the GitHub repository anthropics/claude-code-action (8,784 stars, last pushed yesterday), 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.