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 product-on-purpose/pm-skills --skill tool-foundation-sprint-magic-lensesgit clone --depth 1 https://github.com/product-on-purpose/pm-skillsWrote 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/product-on-purpose/pm-skills/tool-foundation-sprint-magic-lenses)<a href="https://agentmods.dev/skills/product-on-purpose/pm-skills/tool-foundation-sprint-magic-lenses"><img src="https://agentmods.dev/badge/skills/product-on-purpose/pm-skills/tool-foundation-sprint-magic-lenses/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/product-on-purpose/pm-skills/tool-foundation-sprint-magic-lenses"><img src="https://agentmods.dev/badge/skills/product-on-purpose/pm-skills/tool-foundation-sprint-magic-lenses.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
- 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 | $0.00085 | $0.02073 |
| Opus 5 | $0.00043 | $0.01037 |
| Sonnet 5 | $0.00017 | $0.00415 |
| Haiku 4.5 | $0.00009 | $0.00207 |
Grade A, and why
tool-foundation-sprint-magic-lenses 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 9d 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 — 156 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Foundation Sprint Magic Lenses
Day 2 afternoon of a Foundation Sprint. The team evaluates each candidate approach from multiple perspectives, surfaces contradictions, and produces a top bet plus a backup plan. The Decider names both; without an explicit backup, invalidation of the top bet sends the team back to ambiguous debate.
Family contract: docs/reference/skill-families/foundation-sprint-skills-contract.md. This skill is a member of foundation-sprint-skills.
When to Use
- Day 2 afternoon of a Foundation Sprint.
- Approach Options is signed; the team has 3-7 candidate approaches advancing.
- The team has at least 1 team-specific custom lens prepared (per ratified spec decision; classic lenses alone are insufficient).
When NOT to Use
- Approach Options is unresolved or under-numbered (fewer than 3). Force a third option through the approach-options skill first.
- The team has pre-committed to a top bet. Magic Lenses is a sense-making exercise; if the decision is already made, the time is better spent on Founding Hypothesis.
- The team is exhausted and cannot evaluate clearly. Postpone to Day 2 morning of a follow-up sprint rather than rush.
What This Skill Produces
A single bundled artifact with six sections:
- Classic lens charts: customer, pragmatic, growth, money lenses each as a 2x2 plot or qualitative position of every approach.
- Custom lens charts: at least 1 team-specific lens (defensibility, mission fit, founder excitement, learning rate, etc.).
- Pattern review: consistent winners across lenses, contradictions, biggest trade-off the team is making.
- Top bet: the Decider's chosen approach with rationale.
- Backup plan: the runner-up approach the team falls back to if the top bet invalidates.
- Decision rationale: one paragraph explaining why the top bet over the backup.
What ships with it
3 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.
- 9d ago First seen · 156 lines · 85 tokens per session scan A bdb4a08e3c21
tool-foundation-sprint-magic-lenses is a skill published in the GitHub repository product-on-purpose/pm-skills (663 stars, last pushed yesterday), licensed Apache-2.0. It adds 85 tokens to every session and 2,073 once invoked, about $0.0004 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 2026-09-03.
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