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 afaraha8403/balakit --skill design-rationalegit clone --depth 1 https://github.com/afaraha8403/balakitWrote 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/afaraha8403/balakit/design-rationale)<a href="https://agentmods.dev/skills/afaraha8403/balakit/design-rationale"><img src="https://agentmods.dev/badge/skills/afaraha8403/balakit/design-rationale/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/afaraha8403/balakit/design-rationale"><img src="https://agentmods.dev/badge/skills/afaraha8403/balakit/design-rationale.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 | $0.00112 | $0.00702 |
| Opus 5.5 | $0.00045 | $0.00281 |
| Sonnet 5.5 | $0.00022 | $0.00140 |
| Haiku 4.5 | $0.00011 | $0.00070 |
Grade A, and why
design-rationale 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.
What it actually says
Design rationale
Leading words: code is not intent, coverage map, Direct Supported Inferred Speculative Unknown.
Companion to subsystem-walkthrough. That skill is runtime. This one is the
forces that produced the shape.
Copy these steps into the todo list verbatim. Skip with skip: <reason>.
- Parse the target and the question. If vague, state your guess and proceed.
- Code-anchor: paths, symbols,
git blame/git log --follow, PR numbers,gh pr viewwhenghexists. - Coverage map of seven categories. Spawn one investigator per category that exists. Document the null; do not skip the search silently.
- Synthesize with references/epistemics.md. Keep confidence language intact.
- Present. If this investigation precedes a change, add Preserve / Change / Avoid / Risk.
Categories
- Source control — git +
gh. Always run. - Issue / ticket tracker
- Long-form docs
- Real-time chat
- Infrastructure observability
- Error / exception tracking
- Product analytics
Discover tools from what this host actually exposes. Do not require a Cursor
mcps/ directory. Inherit the host model. A missing category is a finding:
"Real-time chat skipped. No matching tool available."
Skip a category only when no tool exists or it is provably irrelevant (a build-time script has no Sentry). Write the reason in Sources Consulted.
Output
The Question / The Code in Question / What We Found / What We Can Reasonably Infer / Competing Hypotheses / What We Don't Know / Sources Consulted (one line per category, including nulls) / Confidence Summary.
Sources Consulted is a 7-row list. A missing tool is a row, not an omitted heading. Do not open with "the user is wrong." Put their guess under Competing Hypotheses.
Reply contract
The synthesis above. Confidence language from epistemics is not rewritten.
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.
- 1mo ago First seen · 72 lines · 112 tokens per session scan A 5a5c6f701c8b
design-rationale is a skill published in the GitHub repository afaraha8403/balakit (1 stars, last pushed 29d ago), licensed MIT. It adds 112 tokens to every session and 702 once invoked, about $0.0004 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 2026-09-11.
Other skills, from other repositories
conventional-commit-message
Generate high-quality Conventional Commit messages for repositories using conventional-changelog-conventionalcommits.
cloudron-app-publishing
Distribute Cloudron apps via CloudronVersions.json version catalogs.
designing-data-intensive-applications
Apply Martin Kleppmann-inspired data-system rules when designing reliability, scalability, consistency, replication, transactions, streams, or schema evolution.
domain-driven-design-distilled
Apply Vaughn Vernon-inspired lightweight DDD rules when using bounded contexts, subdomains, context maps, and tactical modeling without excess ceremony.
implementing-domain-driven-design
Apply Vaughn Vernon-inspired implementation DDD rules when building aggregates, domain events, repositories, application services, or context integrations.
patterns-of-enterprise-application-architecture
Apply Martin Fowler-inspired enterprise architecture rules when choosing layers, service layers, transaction scripts, domain models, repositories, mappers, or DTOs.