# Test a token-saving prompt against hidden tests before you adopt it > One builder ran a popular 'save tokens' prompt for Claude Code over 32 runs with hidden tests. Total cost fell about 9 percent on Opus and 6 percent on Sonnet, up to 20 percent on review tasks and close to zero on bug fixes, with the same quality. Most of the cost was reading code, which the prompt barely touched. - URL: https://paperchasewebb.ai/bots/marketplace/items/test-a-token-saving-prompt-against-hidden-tests-before-you-adopt-it/ - Type: Agent use case pack - Category: Vibe coding - By: PaperChaseWebb - Works with: Claude Code (named in the listing); Plain .md - Price: Free USD - Difficulty: Intermediate - Setup time: 30 min - Time to result: One working session - Format: Markdown (.md) file, test-a-token-saving-prompt-against-hidden-tests-before-you-adopt-it.md - Version: 1.0, updated 2026-10-29 - License: Personal and commercial use. Credit the original source when you share the workflow. ## What you end up with 32 runs is a small sample and the numbers are his own. ## What you get - A plain-language summary of the workflow - A fill-in prompt template - What to watch out for - A link to the original source ## Who it is for Builders who already use AI agents and want a proven workflow they can copy into their own project. ## Tools needed - Claude Code: the agent under test, on Opus and Sonnet - Hidden tests: score quality without the agent seeing them - You need: An AI coding agent or chat model - You need: A small real task to try it on Cost to run: Free with the agent plan you already use. ## How it works 1. **Pick 8 or more real tasks across types: bug fix, feature, review.** Pick 8 or more real tasks across types: bug fix, feature, review. Expected: Done before you move to the next step. 2. **Write hidden tests for each that the agent cannot see.** Write hidden tests for each that the agent cannot see. Expected: Done before you move to the next step. 3. **Run each task with and without the prompt, several times.** Run each task with and without the prompt, several times. Expected: Done before you move to the next step. 4. **Compare cost and pass rate per task type.** Compare cost and pass rate per task type. Expected: Done before you move to the next step. 5. **Adopt the prompt only where it saves money without losing quality.** Adopt the prompt only where it saves money without losing quality. Expected: Done before you move to the next step. ## Sample prompt: Workflow template (Claude Code, Hidden tests) ``` Apply this workflow to [your project]: 1. Pick 8 or more real tasks across types: bug fix, feature, review. 2. Write hidden tests for each that the agent cannot see. 3. Run each task with and without the prompt, several times. 4. Compare cost and pass rate per task type. 5. Adopt the prompt only where it saves money without losing quality. Stop and ask me before anything irreversible: deploys, payments, sends or deletes. ``` Adapted by PaperChaseWebb. Not the original author's prompt. ## Free preview of test-a-token-saving-prompt-against-hidden-tests-before-you-adopt-it.md ````markdown # Test a token-saving prompt against hidden tests before you adopt it PaperChase agent use case (free feed entry), version 1.0. Source: [@mano_sec](https://x.com/mano_sec/status/2115571933899116804), 2026-10-28. ## What they did He compared runs with and without the prompt across task types and checked results with tests the agent could not see. Savings were real but small, and concentrated where the agent writes a lot of prose (reviews), not where it reads a lot of code (bug fixes). ## Worth knowing 32 runs is a small sample and the numbers are his own. The method is what to copy: same tasks, with and without, hidden tests for quality, cost per task type. A separate builder claims 3 to 4 times fewer tokens by asking for a fresh-context follow-up prompt instead of compacting, which is self-reported and worth testing the same way. ```` ## Worth knowing - 32 runs is a small sample and the numbers are his own. The method is what to copy: same tasks, with and without, hidden tests for quality, cost per task type. A separate builder claims 3 to 4 times fewer tokens by asking for a fresh-context follow-up prompt instead of compacting, which is self-reported and worth testing the same way. - Figures are as reported by the original author and were not re-measured by us. ## Questions **Where does this come from?** A public post credited to @mano_sec. Source: https://x.com/mano_sec/status/2115571933899116804 **Is it free?** Yes. Feed entries are free to read and download. ## How to get it Free sample. Download it directly at https://paperchasewebb.ai/bots/marketplace/items/test-a-token-saving-prompt-against-hidden-tests-before-you-adopt-it/, no signup. Seller: PaperChaseWebb Inc., mgmt@paperchasewebb.com