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 skills add hams-ollo/zen-agent-skills --skill test-authorgit clone --depth 1 https://github.com/hams-ollo/zen-agent-skillsWrote 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/hams-ollo/zen-agent-skills/test-author)<a href="https://agentmods.dev/skills/hams-ollo/zen-agent-skills/test-author"><img src="https://agentmods.dev/badge/skills/hams-ollo/zen-agent-skills/test-author/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/skills/hams-ollo/zen-agent-skills/test-author"><img src="https://agentmods.dev/badge/skills/hams-ollo/zen-agent-skills/test-author.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 | $0.00131 | $0.02030 |
| Opus 5.5 | $0.00052 | $0.00812 |
| Sonnet 5.5 | $0.00026 | $0.00406 |
| Haiku 4.5 | $0.00013 | $0.00203 |
Grade A, and why
test-author 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 7d 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 — 162 lines — stays where its author put it; the contents beside it link to each section on GitHub.
test-author
Turn an approved spec into runnable, traceable tests. This is the only spine skill that actually
authors tests: test-quality judges test design, spec-conformance
audits whether code matches a spec, and fix-batch runs whatever tests
exist. test-author is what produces them, from the contract, so that a failing test points back to
the exact scenario it protects.
It runs after implementation and before reconciliation, so test evidence is available when changes
are verified and landed. It composes two lenses by reference and does not restate their rules:
spec-quality gates the input spec, and test-quality
governs every layer and oracle choice.
When to use
- An implementation exists (or a surface is defined) and its approved spec's scenarios need tests.
- Legacy code has no coverage and needs its current behavior pinned before a change (characterization).
- A bug fix needs a regression test that provably fails on the buggy behavior.
When not to use
- You only need to judge whether an existing test is worth keeping: use
test-quality. - You need to check whether the code matches the spec by inspection, not by writing tests: use
spec-conformance. - No spec and no legacy code to characterize: there is nothing to derive tests from yet.
Modes
- Acceptance (an approved spec is present): derive tests from the spec's scenarios.
- Characterization (legacy code, no spec): assert the current observable behavior to pin it before a change, and label the tests as characterization in the name or an adjacent comment.
Infer the mode from the inputs, and let the user override it.
Inputs
Required (acceptance mode):
- Approved spec: a readable spec with
status: approvedand Given/When/Then scenarios carrying stableS-NNNids.
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.
- 7d ago Changed · +7 lines · -23 tokens per session 06825bc1b489
- 1mo ago Changed · +7 lines f0b00e5f90a1
- 2mo ago First seen · 148 lines · 154 tokens per session scan A d64caeae32f7
test-author is a skill published in the GitHub repository hams-ollo/zen-agent-skills (2 stars, last pushed 7d ago), licensed MIT. It adds 131 tokens to every session and 2,030 once invoked, about $0.0005 per session on Opus 5.5. 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
gsd-add-tests
Generate tests for a completed phase based on UAT criteria and implementation.
gsd-eval-review
Audit an executed AI phase's evaluation coverage and produce an EVAL-REVIEW.md remediation plan.
gsd-validate-phase
Retroactively audit and fill Nyquist validation gaps for a completed phase.
gsd-audit-uat
Cross-phase audit of all outstanding UAT and verification items.
tdd
Test-driven development with red-green-refactor loops around vertical slices (tracer bullets), not horizontal layers. Use when asked to "use TDD", "write test-first", "red-green-refactor", "build this with tests", or when a feature has a clear observable contract. The discipline complement to the test/add-tests skills…
verify-before-complete
Block completion claims until verification evidence has been produced in the current message. Use before marking a task/slice/milestone complete, before creating a commit or PR, before saying "it works" or "tests pass", and any time you are about to claim work is done. The rule is: evidence before claims, always …