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/genkovich/sdd/plan-testsnpx skills add genkovich/sdd --skill plan-testsgit clone --depth 1 https://github.com/genkovich/sddWhat 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 | $0.00183 | $0.03113 |
| Opus 5 | $0.00092 | $0.01556 |
| Sonnet 5 | $0.00037 | $0.00623 |
| Haiku 4.5 | $0.00018 | $0.00311 |
Grade A, and why
plan-tests 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 3d 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 — 77 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Skill: plan-tests
Turns an already-specified feature into a test plan: a table that ties every acceptance criterion in spec.md §5 to at least one named test, the levels those tests live at (unit / integration / e2e / contract / load), the integration strategy (a real dependency, spun up throwaway), and the test-data + cleanup approach. The plan is written before a single test exists — the next stage, implement, reads this map and writes the red tests against it, not "however it seems". This file is the spine; the output scaffold lives in templates/test-plan.md.
This skill keeps only its own machinery. Question phrasing is shared → ../_shared/ask-style.md. Depth (inline in the spec vs a separate file) follows the size matrix → ../_shared/size-matrix.md. It names test levels, never test tools — the concrete commands are detected by implement against the repo, not hard-coded here.
Plan prose follows artifact_language — the ## Test plan heading (parsed downstream), test names and level tokens stay English → ../_shared/artifact-language.md.
Owner
QA + the engineer who will implement the feature (co-authors). QA drives the level breakdown and the edge/error cases; the implementing engineer confirms each acceptance criterion has a reachable test and that the integration strategy fits the repo. The Tech Lead signs off that no acceptance criterion is left uncovered.
Inputs
<slug>— the same feature slug every earlier stage used.- Gate (hard-refuse if missing):
docs/features/<slug>/spec.md. Its §5 acceptance criteria are the entire reason this plan exists — each one must map to a test. Ifspec.mdis absent → STOP and point: «runspecify <slug>first — the test plan maps its §5 acceptance criteria to tests». - (Optional)
docs/features/<slug>/data-model.md— the entity shapes tell you what test data to build and what to seed/clean per suite. Read it if present. - (Optional)
docs/features/<slug>/sad.md§6 sequence diagrams — each drawn flow is an e2e candidate; each cross-participant boundary is a contract-test candidate. - (Optional)
docs/features/<slug>/.size— depth hint. Absent → default to M (separatetest-plan.mdfile) and say so loudly in the handoff — «size M (default — no.size; run/sdd:classify-size <slug>)».
What ships with it
1 file 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.
- 3d ago First seen · 77 lines · 183 tokens per session scan A a5340306d00d
plan-tests is a skill published in the GitHub repository genkovich/sdd (118 stars, last pushed 14d ago), licensed MIT. It adds 183 tokens to every session and 3,113 once invoked, about $0.0009 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 2026-08-30.
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