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 mgiovani/cc-arsenal --skill product-prdgit clone --depth 1 https://github.com/mgiovani/cc-arsenalWrote 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/mgiovani/cc-arsenal/product-prd)<a href="https://agentmods.dev/skills/mgiovani/cc-arsenal/product-prd"><img src="https://agentmods.dev/badge/skills/mgiovani/cc-arsenal/product-prd/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/mgiovani/cc-arsenal/product-prd"><img src="https://agentmods.dev/badge/skills/mgiovani/cc-arsenal/product-prd.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00172 | $0.02891 |
| Opus 5.5 | $0.00069 | $0.01156 |
| Sonnet 5.5 | $0.00034 | $0.00578 |
| Haiku 4.5 | $0.00017 | $0.00289 |
Grade A, and why
product-prd 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 22d 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 — 200 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Product PRD
Author the right product doc for the work (sometimes a 3-line ticket, sometimes a full PRD), never more
than the work warrants. This skill writes no application code; it produces the requirements a build
(implement-feature) then works from. Output lands under docs/specs/prd/. <skill-dir> below is this skill's directory.
Input
$ARGUMENTS
Parse the source (first match wins), then read it:
| Pattern | Source | Read via |
|---|---|---|
PROJ-123 |
Jira | jira issue view PROJ-123 |
#42 / owner/repo#42 |
GitHub issue | gh issue view 42 --json title,body,labels,comments |
!123 / PR URL |
GitHub PR | gh pr view 123 --json title,body,files |
| existing path | file/dir | Read it (dir: README, CLAUDE.md/AGENTS.md, key files) |
http(s):// |
URL | WebFetch |
| anything else | plain text | the idea itself |
A trailing --tier brief|one-pager|big and/or --intent validation|execution overrides the assessment.
Prerequisites & fallback
Parallel research and discovery use the Task tool with Explore/haiku subagents. No Task tool? Run
every research and discovery step inline, sequentially: the phase → gate → phase structure below is the
workflow; subagents are just how it parallelizes.
Lean by default
The organizing principle. Default to a single docs/specs/prd/PRD.md and split a section into its own
file only when it outgrows itself. Length is not quality: a bloated PRD and a tight one get rated worlds
apart on content alone. Cut anything that doesn't trace back to the problem, a goal, or a success metric.
- Track position with a single
Phase: Xline in your working notes: no per-turn counters, no resume state. - Cost stop-condition: if the work seems to want a large multi-file tree, stop and ask before emitting
it. Never auto-generate a 12- or 37-file document set. That tree exists only behind
<skill-dir>/scripts/scaffold.py --enterprise <tier>, for a platform-scale program that has genuinely outgrown one file.
What ships with it
19 files 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.
- assets/templates/agent-contract.md 1.0 KB
- assets/templates/alignment-summary.md 991 B
- assets/templates/brief.md 944 B
- assets/templates/decision-log.md 1.5 KB
- assets/templates/decision-question.md 822 B
- assets/templates/one-pager.md 1.6 KB
- assets/templates/prd-full.md 2.1 KB
- assets/templates/prd-root.md 2.1 KB
- assets/templates/prfaq.md 1.5 KB
- assets/templates/requirement.md 2.9 KB
- evals/evals.json 6.5 KB
- evals/trigger-eval.json 1.2 KB
- references/frameworks.md 2.1 KB
- references/phase-workflow.md 6.1 KB
- references/requirement-hygiene.md 3.7 KB
- references/requirement-standards.md 2.8 KB
- scripts/hygiene.py 6.3 KB runs code
- scripts/scaffold.py 8.0 KB runs code
- scripts/validate.py 14 KB runs 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.
- 22d ago Changed · -1 lines 094235e1201f
- 1mo ago Changed · +1 lines 856e676499fe
- 1mo ago Changed c803bdb69d60
- 1mo ago Changed · +1 lines 068c4a1c17de
- 1mo ago First seen · 199 lines · 172 tokens per session scan A 133a5e1fc806
product-prd is a skill published in the GitHub repository mgiovani/cc-arsenal (8 stars, last pushed 2d ago), licensed MIT. It adds 172 tokens to every session and 2,891 once invoked, about $0.0007 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 2026-08-31.
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