Foundation Sprint Magic Lenses
Quick facts
Classification: tool | Version: 0.1.0 | Category: validation | License: Apache-2.0
Try it: /tool-foundation-sprint-magic-lenses "Your context here"
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.
How to Use
Use the /tool-foundation-sprint-magic-lenses slash command:
/tool-foundation-sprint-magic-lenses "Your context here"Or reference the skill file directly: skills/tool-foundation-sprint-magic-lenses/SKILL.md
Output Template
Foundation Sprint Magic Lenses: [Initiative name] (Day 2 Afternoon)
Approach labels: [List the 3-7 approaches from Approach Options with their labels.]
Customer Lens
Question: Which approach do target customers immediately understand and want?
| Approach | Customer perception | Position |
|---|---|---|
| [Label 1] | [Brief reaction] | [HV-HF / HV-LF / LV-HF / LV-LF] |
| [Label 2] | [Brief reaction] | [position] |
| [Label 3] | [Brief reaction] | [position] |
Top per Customer Lens: [Approach label(s)]
Pragmatic Lens
Question: Which approach can the team ship at quality in the build window?
| Approach | Build cost | Risk |
|---|---|---|
| [Label 1] | [Low / Medium / High] | [Low / Medium / High] |
| [Label 2] | […] | […] |
Top per Pragmatic Lens: [Approach label(s)]
Growth Lens
Question: Which approach gives the team a story strong enough to acquire users without paid channels?
| Approach | Why people would tell a friend |
|---|---|
| [Label 1] | [One-line word-of-mouth story] |
| [Label 2] | […] |
Top per Growth Lens: [Approach label(s)]
Money Lens
Question: Which approach has the cleanest path to a paying customer?
| Approach | Monetization story |
|---|---|
| [Label 1] | [Path to revenue] |
| [Label 2] | […] |
Top per Money Lens: [Approach label(s)]
Custom Lens [N]: [Name]
Question: [The lens-specific question the team needs answered.]
| Approach | [Lens-specific dimension] |
|---|---|
| [Label 1] | [Assessment] |
| [Label 2] | […] |
Top per [Custom Lens]: [Approach label(s)]
[Add additional custom lenses as needed. Minimum 1 custom lens required.]
Pattern Review
Consistent winners: [Approaches that scored top half of 3+ lenses.]
Consistent losers (eliminated):
- Label: [Why this approach drops out.]
Contradictions:
- [Contradiction pattern]: [Which approaches win one lens hard but lose another?]
Biggest trade-off: [Name it explicitly. The Decider’s choice is along this axis.]
Top Bet (Decider Supervote)
Top bet: [Approach label and name].
Rationale: [Two or three sentences naming the trade-off the Decider is taking. Should be defensible in language.]
Backup Plan
Backup: [Distinct approach label and name].
[One paragraph explaining when the team falls back to this. The backup MUST be strategically distinct from the top bet, not an iteration of it.]
Decision Rationale
[One paragraph explaining why this top bet over this backup. This paragraph becomes the spine of the Founding Hypothesis’s “why we believe this” section.]
Decider Checkpoint
Decider sign-off required before Founding Hypothesis writing begins.
- Decider names the top bet with explicit rationale.
- Decider names the backup as a distinct strategic direction (not an iteration).
- Decider commits to testing the top bet via the planned next step (Design Sprint, customer research, experiment).
- Decider acknowledges the trade-off being taken; the team agrees that re-litigation requires invalidation evidence, not preference shifts.
Signed: [Decider name, role], [ISO date and local time]
Example Output
Foundation Sprint Magic Lenses: Brainshelf (Day 2 Afternoon)
Foundation Sprint Magic Lenses: Brainshelf (Day 2 Afternoon)
The Brainshelf team’s Day 2 PM lens evaluation. Top bet and backup named.
Approach labels: A=Yellow Camera, B=Blue Library, C=Green Voice, D=Red Bookstore, E=Purple Triage.
Customer Lens
Question: Which approach do target customers immediately understand and want?
| Approach | Customer perception | Position |
|---|---|---|
| Yellow Camera | ”I get it. Point and capture.” | HV-HF (high value, high feasibility) |
| Blue Library | ”Pretty. But I don’t have books to put in it yet.” | MV-HF (medium value, chicken-and-egg) |
| Green Voice | ”Cool, but I talk to my phone in public?” | MV-LF (mixed appetite) |
| Red Bookstore | ”Wait, you do that?” (delight) | VHV-LF (very high value, narrow context) |
| Purple Triage | ”Like Pocket for books. Sure.” | MV-HF (low novelty) |
Top per Customer Lens: Yellow (broad), Red (deep delight).
Pragmatic Lens
Question: Which approach can the team realistically ship at quality in 8-10 weeks?
| Approach | Build cost | Risk |
|---|---|---|
| Yellow Camera | Medium (OCR + cover-recognition; Apple Vision API available) | Acceptable |
| Blue Library | Low (CRUD + UI polish) | Low |
| Green Voice | High (voice quality + book entity resolution) | High |
| Red Bookstore | High (geofence + offline book DB) | Very high |
| Purple Triage | Low-medium (share extension + queue UI) | Low |
Top per Pragmatic Lens: Blue, Yellow.
Growth Lens
Question: Which approach gives the team a story strong enough to acquire users without paid channels?
| Approach | Why people would tell a friend |
|---|---|
| Yellow Camera | ”I just snap books, it’s the easiest tracker I’ve used.” Decent. |
| Blue Library | ”My library looks nice.” Low signal. |
| Green Voice | ”I talk to it and it just works.” High novelty IF it works. |
| Red Bookstore | ”It tells me at the bookstore if I’ve already read it.” Highest novelty. |
| Purple Triage | ”Pocket for books.” Low novelty. |
Top per Growth Lens: Red, Green (if voice quality holds), Yellow.
Money Lens
Question: Which approach has the cleanest path to a paying customer?
| Approach | Monetization story |
|---|---|
| Yellow Camera | Free tier with limit; paid sync + cross-device. Familiar. |
| Blue Library | Same as Yellow; library-as-portfolio enables aesthetic premium. |
| Green Voice | Same as Yellow; voice is a free differentiator, not a paywall. |
| Red Bookstore | Bookstore mode could be a premium feature (geofence intelligence). |
| Purple Triage | Triage capacity could tier (10 / 50 / unlimited). Pocket precedent. |
Top per Money Lens: All approaches have similar models. Slight edge to Blue (visual library could be a premium aesthetic) and Red (premium context awareness).
Custom Lens 1: Defensibility Against Goodreads / Amazon
Question: If Goodreads decided to copy this in 6 months, which approach would still feel different?
| Approach | Defensible? |
|---|---|
| Yellow Camera | No. Goodreads has cover scanning today. |
| Blue Library | Partially. Brainshelf’s principles (private, no feed) make this strategically distinct. |
| Green Voice | Yes. Goodreads is unlikely to commit to voice; mobile-app-first companies dominate. |
| Red Bookstore | Yes. Goodreads is owned by Amazon; geofencing physical bookstores is awkward for them. |
| Purple Triage | Partially. The triage pattern is well-known. |
Top per Defensibility Lens: Red, Green.
Pattern Review
Consistent winners: Yellow Camera (positive on 4 of 5 lenses), Red Bookstore (positive on 4 of 5 lenses).
Consistent losers (eliminated):
- Blue Library: chicken-and-egg problem (empty library at launch); not strong enough on its own.
- Green Voice: feasibility risk too high for the differentiation it provides; voice can be a feature inside another approach later.
- Purple Triage: doesn’t carry the “did I read this?” recall pain hard enough.
Contradictions:
- Red is high on Customer + Growth + Money + Defensibility but failing Pragmatic. Hardest to ship; highest leverage if shipped.
- Yellow is positive across all five but never #1 on any single lens. Strong consistent middle.
Biggest trade-off: Boring-and-shippable (Yellow) versus risky-and-distinctive (Red).
Top Bet (Decider Supervote)
Top bet: Approach A (Yellow Camera-First Capture).
Rationale: The riskiest assumption for Brainshelf is not “is this concept appealing” (Red would tell us that). The riskiest assumption is “will people switch from doing nothing to using a tracking app at all if friction drops below 3 seconds?” Yellow tests that hypothesis most directly. If Yellow succeeds, Red becomes a Phase 2 differentiator. If Yellow fails (people don’t capture even with no friction), Red doesn’t save the product.
Backup Plan
Backup: Approach D (Red Bookstore Mode).
If the Design Sprint test of Yellow shows weak adoption (“customers nod but don’t actually capture”), Brainshelf pivots to lead with bookstore-mode delight. Recall-at-context becomes the wedge, capture follows. This is a strategically distinct direction (context-driven recall) not an iteration of Yellow.
Decision Rationale
The team converged on Yellow over Red because the test value of Yellow is higher. Validating the core capture-speed differentiator early de-risks every downstream investment. Red is more delightful but tests a narrower (and later) part of the product. Better to know if the foundation works first.
Decider Checkpoint
Decider sign-off required before Founding Hypothesis writing begins.
- Jamie names Yellow (Camera-First Capture) as the top bet.
- Jamie names Red (Bookstore Mode) as the backup, strategically distinct from Yellow.
- Jamie commits to NOT building Yellow as a Camera with Red features grafted on. They are distinct approaches with distinct testing paths.
- Jamie agrees to test the Yellow top bet via the planned Design Sprint week of May 26.
Signed: Jamie (founder, PM), 2026-05-14 15:40 PT