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.
npx agentmods add skills/grodowski/undercover-claude/coveragenpx skills add grodowski/undercover-claude --skill coveragegit clone --depth 1 https://github.com/grodowski/undercover-claudeWrote 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/skills/grodowski/undercover-claude/coverage)<a href="https://agentmods.dev/skills/grodowski/undercover-claude/coverage"><img src="https://agentmods.dev/badge/skills/grodowski/undercover-claude/coverage.svg" alt="Measured on agentmods" 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 | $0.00047 | $0.01298 |
| Opus 5 | $0.00023 | $0.00649 |
| Sonnet 5 | $0.00009 | $0.00260 |
| Haiku 4.5 | $0.00005 | $0.00130 |
Grade A, and why
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 5d 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.
How it starts
The opening of the file, as written. The whole thing — 137 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Undercover Coverage Feedback
Routing
The user may have stated an intent after the command (shown below as $ARGUMENTS).
Use it to decide what to do, then read the matching reference file before acting:
- Set up coverage in a Ruby project (SimpleCov, Gemfile,
.undercover, permissions) → readreferences/setup.md - Set up CI (UndercoverCI or GitHub Actions; also CircleCI and parallel test merging) → read
references/ci.md - Read/address UndercoverCI feedback on a PR → read
references/pr-feedback.md - Skip coverage for a file (
:nocov:,add_filter,--exclude-files) → readreferences/skipping.md - Run the feedback loop after tests, or anything else → use the loop below (the default)
Stated intent: $ARGUMENTS
If no intent was given, default to the feedback loop.
Coverage Feedback Loop
After every test run, run undercover to check for coverage gaps.
Only use --include-files when you ran a partial test suite. Full suite → no flag.
Full test suite:
bundle exec undercover --format json
Partial test run (single file or subset — undercover must match scope):
bundle exec undercover --format json --include-files "app/models/foo.rb"
bundle exec undercover --format json --include-files "app/models/*.rb,app/services/foo*.rb"
--include-files accepts comma-separated glob patterns. When running a subset of
tests, SimpleCov only has coverage data for loaded files. Without --include-files,
undercover will falsely flag all other changed files as uncovered.
Workflow:
- Run tests
- Run
bundle exec undercover --format json(scoped with--include-filesif partial) - If gaps found: write tests for uncovered code. Prefer real tests over
:nocov:— only use:nocov:when the code genuinely cannot or should not be tested (seereferences/skipping.md). Only delete code if you are certain it is dead/unreachable — understand why it's uncovered before removing it - Repeat until undercover exits 0
JSON output format
What ships with it
4 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.
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.
- 5d ago First seen · 137 lines · 47 tokens per session scan A 3a52b8b13b7f
coverage is a skill published in the GitHub repository grodowski/undercover-claude (2 stars, last pushed 2mo ago), licensed MIT. It adds 47 tokens to every session and 1,298 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 2026-08-31.
Other skills, from other repositories
agent-platform-rag-engine-management
Manage and query Agent Platform RAG Engine Corpora and retrieve grounded contexts using the Google GenAI SDK. Use when listing RAG corpora or files, inspecting a corpus, retrieving contexts, or generating content grounded in a RAG corpus. Do not use for standard database queries (use SQL/Spanner skills), Google…
gke-reliability
Improves GKE workload reliability, using PDBs, health probes, and topology spread constraints. Use when configuring GKE workload reliability, setting up PDBs, or configuring GKE health probes (liveness, readiness, startup). Don't use for disaster recovery setup or full cluster backups (use gke-backup-dr instead).
gke-workload-security
Audits, configures, and hardens workload-level security controls for Google Kubernetes Engine (GKE) applications and namespaces. Covers running cluster security audits (auditcluster.sh), configuring Workload Identity Federation (impersonation, KSA/GSA binding, and pod setup), enforcing Network Policies (default-deny…
agent-platform-model-registry
Agent Platform Model Registry Management. Use when you need to upload, list, describe, update, or delete machine learning models (and their versions) in the Agent Platform Model Registry. Don't use for model training, model deployment to endpoints, or managing non-Agent Platform models.
google-cloud-solution-agentic-analytics-spark-knowledge-catalog
Discovers requirements and generates guidance to design and deploy a governed, secure agentic-analytics solution for data that's distributed across Google Cloud, other cloud providers, or on-premises. Data that's outside Google Cloud (such as data from Databricks, Snowflake, Salesforce, SAP, or Oracle systems) is…
twitter-reader
Read Twitter/X for financial research using opencli (read-only). Use this skill whenever the user wants to read their Twitter feed, search for financial tweets, view bookmarks, look up user profiles, or gather market sentiment from Twitter/X. Triggers include: "check my feed", "search Twitter for", "show my…