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 saffron-health/libretto --skill spec-reviewgit clone --depth 1 https://github.com/saffron-health/librettoWrote 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/saffron-health/libretto/spec-review)<a href="https://agentmods.dev/skills/saffron-health/libretto/spec-review"><img src="https://agentmods.dev/badge/skills/saffron-health/libretto/spec-review/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/saffron-health/libretto/spec-review"><img src="https://agentmods.dev/badge/skills/saffron-health/libretto/spec-review.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 | $0.00037 | $0.00983 |
| Opus 5 | $0.00018 | $0.00491 |
| Sonnet 5 | $0.00007 | $0.00197 |
| Haiku 4.5 | $0.00004 | $0.00098 |
Grade A, and why
spec-review 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 12d 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- spec-review — 89% identical, 18 lines differ
How it starts
The opening of the file, as written. The whole thing — 97 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Review the spec the user points you to. Follow these steps in order.
Step 1: Read the spec
Read the spec file the user references.
Step 2: Research the codebase
Use sub-agents to read every file listed in the spec's "Important files" section. For each file, understand its current state well enough to evaluate whether the spec's proposed changes are correct and complete.
If the spec references external libraries or APIs, look up their documentation.
Step 3: Evaluate
Assess the spec against three categories. For each finding, cite the specific spec line or section and the relevant source file and line number.
Under-specified areas
Find places where the spec leaves ambiguous decisions that should have explicit design intent from the user. Examples:
- A phase says "update the handler" but two handlers exist and the spec does not say which one
- A schema change is described but the migration path for existing data on disk is not addressed
- A new dependency is introduced between two modules but the spec does not state which module owns the interface
- Error handling or edge cases are not mentioned for a path that can clearly fail
- The spec describes behavior but does not specify what happens when the precondition is not met
Do not flag things that are obviously implied by context. Flag things where a reasonable implementer would have to guess.
Bugs
Find design-level logical errors — things that would send an implementer down the wrong path or produce incorrect behavior that tooling won't catch. Examples:
- A phase deletes a module but a later phase depends on the concept it provided (not just the import — the typecheck catches that)
- The spec contradicts its own goals or non-goals (e.g., says "calendar support later" but removes the only calendar mechanism without acknowledging it)
- A fan-out loop creates sessions but nothing deduplicates if the same event matches the same trigger twice
- The spec assumes a data shape or behavior that doesn't match reality in the codebase
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.
- 12d ago First seen · 97 lines · 37 tokens per session scan A 95c3be5d1a00
spec-review is a skill published in the GitHub repository saffron-health/libretto (890 stars, last pushed 22d ago), licensed MIT. It adds 37 tokens to every session and 983 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 2026-08-30.
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