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 isaacsight/kernel --skill test-driven-developmentgit clone --depth 1 https://github.com/isaacsight/kernelWrote 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/isaacsight/kernel/test-driven-development)<a href="https://agentmods.dev/skills/isaacsight/kernel/test-driven-development"><img src="https://agentmods.dev/badge/skills/isaacsight/kernel/test-driven-development/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/isaacsight/kernel/test-driven-development"><img src="https://agentmods.dev/badge/skills/isaacsight/kernel/test-driven-development.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 3 findings, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium MCP Rug Pull · line 53 npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.Fix: Pin the version: npx @scope/[email protected]
- medium MCP Rug Pull · line 74 npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.Fix: Pin the version: npx @scope/[email protected]
- medium MCP Rug Pull · line 54 npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.Fix: Pin the version: npx @scope/[email protected]
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 | $0.00024 | $0.00667 |
| Opus 5.5 | $0.00010 | $0.00267 |
| Sonnet 5.5 | $0.00005 | $0.00133 |
| Haiku 4.5 | $0.00002 | $0.00067 |
Grade A, and why
test-driven-development 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.
How it starts
The opening of the file, as written. The whole thing — 75 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Test-Driven Development
Iron Law
THE FIRST COMMIT ON ANY BEHAVIOR CHANGE IS A FAILING TEST.
No exceptions. Not "I'll add tests after." Not "this is too small." The failing test proves you understood the behavior before you wrote it.
Why
- Writing the test first forces you to design the interface, not the implementation.
- A failing test that turns green is the only honest proof the fix works.
- Tests written after the fact confirm what you already did, not what you should have done.
- Coverage that grows alongside code never has a "we should add tests" backlog.
The Cycle
RED
- Decide what the new behavior is, in one sentence.
- Write the smallest test that would fail if the behavior is missing.
- Run it. Confirm it fails for the right reason (not a typo, not a missing import).
GREEN
- Write the minimum code that makes the test pass.
- No extra features. No refactoring yet. No "while I'm here."
- Run the test. Confirm green.
REFACTOR
- Now — and only now — clean up the implementation.
- Rename, extract, deduplicate. Tests still green the whole time.
- If a refactor turns a test red, you changed behavior — revert and think.
kbot Toolchain
- Framework: Vitest (
.test.tsnext to source). - Runner:
npx vitest run(one-shot) ornpx vitest(watch). - Typecheck gate:
npx tsc --noEmitbefore every commit. Strict mode is non-negotiable. - UI tests:
@testing-library/react. - E2E: Playwright (
npm run test:e2e).
Mocking Policy
- Mock Supabase. Never call the real API in tests.
- Mock the Claude proxy. Never call the real API in tests.
- Do NOT mock your own pure functions — test them directly.
- Do NOT mock file I/O — use
tmpdir()fixtures.
Anti-Patterns
- Tests that assert implementation details (internal method calls) instead of observable behavior.
- Tests that share state between cases. Each test starts clean.
- Test names like
it('works'). Name the behavior:it('rejects unauthenticated requests'). - "Fix the test" when the test correctly catches a regression. Fix the code.
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 · 75 lines · 24 tokens per session scan A 24ec33a662ed
test-driven-development is a skill published in the GitHub repository isaacsight/kernel (16 stars, last pushed 1mo ago), licensed MIT. It adds 24 tokens to every session and 667 once invoked, about $0.0001 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 2026-09-03.
Other skills, from other repositories
ocm-integrations
Use OCM workspace integrations exposed by the native mcp.servers.ocm MCP server. Trigger when a user asks to use connected workspace apps or external SaaS tools such as Google Workspace, GitHub, Jira, Linear, Slack, Notion, custom REST APIs, OpenAPI tools, or remote MCP servers through OCM.
engram-testing-coverage
TDD and coverage standards for Engram. Trigger: When implementing behavior changes in any package.
conductor-implement
Execute tasks from a track's implementation plan following TDD workflow.
principle-test-behavior-not-implementation
Apply when you write, change, or keep a test. Assert what the code's users can observe, so that the test fails when that behavior breaks and keeps passing when only the internals change.
iterative-development
TDD iteration loops using Claude Code Stop hooks - runs tests after each response, feeds failures back automatically.
python
Python development with ruff, mypy, pytest - TDD and type safety.