Borrowing it
Nothing to install: this file belongs to saski/arnesto. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/saski/arnesto/main/.agents/skills/working-backwards/SKILL.mdgit clone --depth 1 https://github.com/saski/arnestoWrote 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/saski/arnesto/working-backwards)<a href="https://agentmods.dev/skills/saski/arnesto/working-backwards"><img src="https://agentmods.dev/badge/skills/saski/arnesto/working-backwards.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 5.1 | $0.00080 | $0.00510 |
| Opus 5 | $0.00040 | $0.00255 |
| Sonnet 5 | $0.00016 | $0.00102 |
| Haiku 4.5 | $0.00008 | $0.00051 |
Grade A, and why
working-backwards 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 3d 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.
This is a copy
100% identical to working-backwards — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 52 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Domain Context
This skill implements a proven product management framework. The approach combines best practices from industry leaders and is designed for practical application in day-to-day PM work.
Input Requirements
- Context about your product, feature, or problem
- Relevant data, research, or constraints (recommended but optional)
- Clear articulation of what you're trying to achieve
Working Backwards
What It Is
Working Backwards is Amazon's product development methodology. The core insight: start with the customer problem and work backward to the solution, not the other way around.
Most teams work forward: "We have this technology/capability/idea — what can we build with it?" Working Backwards inverts this: "What problem does the customer have? What would the ideal solution look like? Now, how do we build it?"
The mechanism: Write an internal press release and FAQ before building anything. If you can't write a compelling press release, you don't have a compelling product.
As Jeff Bezos put it: "We took it as an article of faith — if we served customers well, if we prioritized customers and delivered for them, things like sales, revenue, and free cash flow would follow."
When to Use It
Use Working Backwards when you need to:
- Define a new product or major feature before committing resources
- Evaluate competing product ideas and choose which to build
- Align stakeholders on what you're building and why
- Force clarity on vague product concepts
- Prevent building solutions in search of problems
- Create a shared vision that engineering, design, and leadership can rally around
- Decide whether an idea is worth pursuing at all
When Not to Use It
- The work is incremental optimization (A/B tests, bug fixes)
- You're executing on an already-defined product
- The scope is too small to warrant the overhead
Resources
Books:
- Working Backwards by Bill Carr and Colin Bryar
- The Everything Store by Brad Stone
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.
- 3d ago First seen · 52 lines · 80 tokens per session scan A 3ba00648987b
working-backwards is a skill published in the GitHub repository saski/arnesto (5 stars, last pushed today), licensed Unlicense. It adds 80 tokens to every session and 510 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to working-backwards, differing in 0 lines, and is treated as a copy.
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