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/nickpolyder/np.copilot.config/feature-design-docnpx skills add NickPolyder/NP.CoPilot.Config --skill feature-design-docgit clone --depth 1 https://github.com/NickPolyder/NP.CoPilot.ConfigWrote 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/nickpolyder/np.copilot.config/feature-design-doc)<a href="https://agentmods.dev/skills/nickpolyder/np.copilot.config/feature-design-doc"><img src="https://agentmods.dev/badge/skills/nickpolyder/np.copilot.config/feature-design-doc.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 | $0.00043 | $0.01080 |
| Opus 5 | $0.00022 | $0.00540 |
| Sonnet 5 | $0.00009 | $0.00216 |
| Haiku 4.5 | $0.00004 | $0.00108 |
Grade A, and why
feature-design-doc 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 5d 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.
Purpose
Intent (anchor): Generate a feature
design.mdthat a developer, including a junior developer, could implement from. Always: ground the design in prior codebase research; ask 2-3 informed clarifying questions; include every required design section; gate before task generation. Never: invent patterns that contradict the codebase, generate implementation tasks, or write production code.
Shared policy: Follow
instructions/coordination.instructions.mdfor precedence, invocation, delegation, and handoffs. Applyinstructions/workflow.instructions.mdfor proportional work and verification.
You are producing a design document that translates approved research and feature intent into a clear implementation blueprint.
Your goals are to:
- Clarify scope — ask only the key questions needed to resolve ambiguity.
- Document the design — create
design.mdwith the required sections and enough detail to implement. - Ground decisions — align with existing codebase patterns, abstractions, constraints, and project instructions.
- Prepare handoff — make the next atomic step,
task-breakdown, straightforward.
When to use this skill
Use this skill whenever:
- Codebase research is complete and the user approves moving to design.
- A feature needs a standalone
docs/features/{feature-name}/design.md. - The user asks for a feature design document grounded in an existing repository.
- You need the second atomic step in the chain:
codebase-research→feature-design-doc→task-breakdown→implementation-runner.
Do not use this skill for:
- Initial codebase investigation — use
codebase-research. - Generating implementation tasks — use
task-breakdown. - Executing code changes — use
implementation-runner. - Comprehensive plan-only orchestration — recommend
feature-planninginstead of nesting it.
Workflow
Produce a design document that a developer (including a junior) could implement from.
- Ask 2-3 clarifying questions — scope, constraints, preferences. Keep questions informed by the research.
- Generate
docs/features/{feature-name}/design.mdwith these sections:
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.
- 5d ago First seen · 118 lines · 43 tokens per session scan A 8910385de271
feature-design-doc is a skill published in the GitHub repository NickPolyder/NP.CoPilot.Config (2 stars, last pushed 10d ago), licensed MIT. It adds 43 tokens to every session and 1,080 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…
chat-pet-sprite-creation
Use when creating or changing VS Code chat pet sprite art, sprite sheets, state animations, eye treatments, Stable/Insiders variants, or pet transitions under src/vs/workbench/contrib/chat/browser/widget/media/chatPet.
cpu-profile-analysis
Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…
insight-error-page
Write or audit an insight-kind error page for the Next.js dev overlay. Use when creating a new errors/ .mdx page, auditing an existing one, or checking that a page matches the framework fix cards. Covers page structure, title alignment, FixCard cards with Copy prompt button, code snippets, terminology verification…