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 nacif-software/skills --skill design-featuregit clone --depth 1 https://github.com/nacif-software/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/nacif-software/skills/design-feature)<a href="https://agentmods.dev/skills/nacif-software/skills/design-feature"><img src="https://agentmods.dev/badge/skills/nacif-software/skills/design-feature.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 | $0.00036 | $0.00923 |
| Opus 5 | $0.00018 | $0.00462 |
| Sonnet 5 | $0.00007 | $0.00185 |
| Haiku 4.5 | $0.00004 | $0.00092 |
Grade A, and why
design-feature 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 8d 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 — 118 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Design Feature
Purpose
Turn a feature idea into a clear design artifact before implementation. The workflow
may stop at the design, continue into an implementation plan, or hand off to
plan-implementation.
When to use
- Use for new features, product changes, architecture-affecting refactors, and unclear implementation requests.
- Use when the user says "design", "spec", "PRD", "plan this", "grill me", or "help me think through this".
- Do not use for small mechanical edits whose requirements and files are already explicit.
Procedure
- Discover local context before asking questions:
- Read repo instruction files such as
AGENTS.md,CLAUDE.md,CONTRIBUTING.md, and relevant docs. - Inspect nearby code, tests, routes, package scripts, or schemas that define the current shape.
- Summarize only the facts that affect the design.
- Read repo instruction files such as
- Start a decision map:
- Resolved decisions.
- Open questions.
- Assumptions.
- Out-of-scope items.
- Ask one linked question at a time. Each question must resolve a real branch in the decision map. Prefer a recommendation with trade-offs.
- When enough is known, present 2-3 viable approaches and recommend one.
- Draft the design in sections:
- Problem and goal.
- User-visible behavior.
- Technical approach.
- Interfaces, data flow, or contracts.
- Edge cases and failure modes.
- Test and verification strategy.
- Out of scope.
- Ask the user to approve or revise the design.
- Write the design doc in the repo's preferred docs location. If no convention
exists, use
docs/designs/YYYY-MM-DD-<feature>.md. - Self-review the design for placeholders, contradictions, unresolved decisions, unclear acceptance criteria, and accidental scope creep.
- Offer the next step:
- Stop at design.
- Create an implementation plan with
plan-implementation. - Create a plan and test strategy with
test-strategy. - Create a plan, test strategy, and PR shape with
pr-boundary. - Create a plan, test strategy, PR shape, and review it with
review-plan. - Create a plan, test strategy, PR shape, review it, and continue into
execute-plan.
- If the user chooses implementation for non-trivial work, chain through
plan-implementation,test-strategy,pr-boundary,review-plan, and thenexecute-plan. Do not jump from design directly to execution. - Use
verification-gatebefore claiming the design artifact or any chained artifact is complete.
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.
- 8d ago First seen · 118 lines · 36 tokens per session scan A 5b82f5c8e12f
design-feature is a skill published in the GitHub repository nacif-software/skills (2 stars, last pushed 1mo ago), licensed MIT. It adds 36 tokens to every session and 923 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
systematic-debugging
Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.
local-ai-agents
Build local-first AI agents that run entirely on a developer workstation with Microsoft Foundry Local and Qwen function-calling models. Covers Small Language Models (SLMs), the OpenAI-compatible local endpoint, sandboxed local tools, local RAG with Chroma, local MCP servers, hybrid cloud/local routing, and the…
next-cache-components-adoption
Turn on Cache Components in a Next.js app and resolve the blocking routes it surfaces. Use when the user wants to enable, adopt, or migrate to Cache Components, flip the cacheComponents flag, work through a flood of blocking-prerender / instant validation errors, run the cache-components-instant-false codemod, or…
next-cache-components-optimizer
Drive a Next.js route to instant navigation by setting up an agentic loop, under Cache Components / PPR, on initial load (hard navigation) and client-side navigation (soft navigation). Encode the goal as a failing @next/playwright instant() e2e and work it to green, one verified route at a time; the shipped test then…
next-partial-prefetching-adoption
Turn on Partial Prefetching in a Next.js app and work through the insights it surfaces. Use when the user wants to enable or adopt Partial Prefetching, flip the partialPrefetching flag, opt routes in with export const prefetch = 'partial', audit Link prefetch={true} behavior, preserve existing prefetched UI with…
chronicle
Analyze Copilot session history for standup reports, usage tips, session search, and session reindexing. Use when the user asks for a standup, daily summary, usage tips, workflow recommendations, wants to search or find past sessions by keyword/file/PR, wants to reindex their session store, or asks about deleting…