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/felipepg22/fpgskills/implementation-spec-writernpx skills add felipepg22/FPGSkills --skill implementation-spec-writergit clone --depth 1 https://github.com/felipepg22/FPGSkillsWrote 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/felipepg22/fpgskills/implementation-spec-writer)<a href="https://agentmods.dev/skills/felipepg22/fpgskills/implementation-spec-writer"><img src="https://agentmods.dev/badge/skills/felipepg22/fpgskills/implementation-spec-writer.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 | $0.00030 | $0.00179 |
| Opus 5 | $0.00015 | $0.00089 |
| Sonnet 5 | $0.00006 | $0.00036 |
| Haiku 4.5 | $0.00003 | $0.00018 |
Grade A, and why
implementation-spec-writer 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.
What it actually says
Implementation Spec Writer
Create the implementation contract an engineer or coding agent will execute. Produce the specification only; leave task publication and implementation to separate workflows.
- Read references/workflow.md completely and follow its intake, evidence, decision, and write sequence.
- Read references/spec-schema.md completely before drafting. Use its document contract and identifiers.
- Read references/readiness.md completely before writing. Validate the complete draft against every applicable check.
- Create or safely update exactly one Markdown file. Report its path, status, material assumptions, and unresolved decisions.
What ships with it
6 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.
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 · 16 lines · 30 tokens per session scan A 6747f87efed7
implementation-spec-writer is a skill published in the GitHub repository felipepg22/FPGSkills (11 stars, last pushed today), licensed MIT. It adds 30 tokens to every session and 179 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.
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