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/caiaffa/claude-code-ultimate-engineering-system/prd-gap-detectornpx skills add caiaffa/claude-code-ultimate-engineering-system --skill prd-gap-detectorgit clone --depth 1 https://github.com/caiaffa/claude-code-ultimate-engineering-systemWrote 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/caiaffa/claude-code-ultimate-engineering-system/prd-gap-detector)<a href="https://agentmods.dev/skills/caiaffa/claude-code-ultimate-engineering-system/prd-gap-detector"><img src="https://agentmods.dev/badge/skills/caiaffa/claude-code-ultimate-engineering-system/prd-gap-detector.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 | $0.00025 | $0.00492 |
| Opus 5 | $0.00013 | $0.00246 |
| Sonnet 5 | $0.00005 | $0.00098 |
| Haiku 4.5 | $0.00003 | $0.00049 |
Grade A, and why
prd-gap-detector 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 4d 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
Mission
Find the omissions that turn promising PRDs into expensive surprises.
When to use
- Checking PRD completeness.
- Looking for hidden engineering cost.
- Validating measurement and rollout quality.
- Surfacing operational, data, support, or security gaps.
Handoff
- Receives from: prd-challenger (after initial challenge).
- Hands off to: engineering-economics (cost assessment), principal-engineer (for revision).
Completeness scan
Check whether the PRD explicitly addresses each item. "Implied" is not "addressed":
| Section | Present? | Quality |
|---|---|---|
| Problem statement with evidence | ||
| Baseline metric(s) with source | ||
| Non-goals (explicit scope boundary) | ||
| Primary success metric | ||
| Secondary metrics | ||
| Guardrail metrics (what must NOT get worse) | ||
| Target with timeline | ||
| Owner after launch | ||
| Rollout plan | ||
| Rollback plan | ||
| Support impact assessment | ||
| Security implications | ||
| Data/migration requirements | ||
| Observability requirements | ||
| Decision rule (when to stop or pivot) |
Hidden cost areas that PRDs almost always miss
- Data migration — does the feature require backfilling old data?
- Observability — new dashboards, alerts, SLOs needed?
- Support burden — new failure modes that support team needs to handle?
- Security — new auth rules, permission changes, data exposure?
- API compatibility — does this break existing consumers?
- Operational burden — who monitors this at 3 AM?
- Documentation — API docs, user guides, internal wiki?
Output format
- Completeness score (X/15 sections addressed)
- Critical gaps (missing items that block approval)
- Hidden engineering work (undisclosed cost areas)
- Ambiguity risks (things that could be interpreted multiple ways)
- Required additions (specific sections to write, with guidance)
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.
- 4d ago First seen · 55 lines · 25 tokens per session scan A b650b10b7fde
prd-gap-detector is a skill published in the GitHub repository caiaffa/claude-code-ultimate-engineering-system (17 stars, last pushed 2mo ago), licensed MIT. It adds 25 tokens to every session and 492 once invoked, about $0.0001 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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