plugins/prompt-engineer/skills/prompt-testing/SKILL.md
A/B testing and performance metrics for prompts. Use when: comparing two prompt variants, defining quality/efficiency/robustness metrics, or deciding whether to adopt a challenger prompt over a baseline.
npx skillsauth add fusengine/agents prompt-testingInstall this skill globally with one command. Works with Claude Code, Cursor, and Windsurf.
3 of 9 scanners reported clean
Some scanners were skipped, did not run, or reported a non-clean status. Review each row below.
Skill for testing, comparing, and measuring prompt performance.
1. DEFINE
└── Test objective
└── Metrics to measure
└── Success criteria
2. PREPARE
└── Variants A and B
└── Test dataset
└── Baseline (if existing)
3. EXECUTE
└── Run on dataset
└── Collect results
└── Document observations
4. ANALYZE
└── Calculate metrics
└── Compare variants
└── Identify patterns
5. DECIDE
└── Recommendation
└── Statistical confidence
└── Next iterations
| Metric | Description | Calculation | |--------|-------------|-------------| | Accuracy | Correct responses | Correct / Total | | Compliance | Format adherence | Compliant / Total | | Consistency | Response stability | 1 - Variance | | Relevance | Meeting the need | Average score (1-5) |
| Metric | Description | Calculation | |--------|-------------|-------------| | Tokens Input | Prompt size | Token count | | Tokens Output | Response size | Token count | | Latency | Response time | ms | | Cost | Price per request | Tokens × Price |
| Metric | Description | Calculation | |--------|-------------|-------------| | Edge Cases | Edge case handling | Passed / Total | | Jailbreak Resist | Bypass resistance | Blocked / Attempts | | Error Recovery | Error recovery | Recovered / Errors |
For full definitions, thresholds, and the UX metrics category, see metrics.md. For the test dataset and report formats, see templates.md.
# Create a test
/prompt test create --name "Test v1" --dataset tests.json
# Run an A/B test
/prompt test run --a prompt_a.md --b prompt_b.md --dataset tests.json
# View results
/prompt test results --id test_001
# Compare two tests
/prompt test compare --tests test_001,test_002
IF:
- Accuracy B >= Accuracy A
AND (Tokens B <= Tokens A * 1.1 OR accuracy improvement > 5%)
AND no regression on edge cases
THEN:
→ Adopt B
ELSE IF:
- Accuracy improvement > 10%
AND token regression < 20%
THEN:
→ Consider B (acceptable trade-off)
ELSE:
→ Keep A or iterate
testing
Copy self-audit and ban-lists — filler verbs/hype adjectives, slop placeholder names, fake-precise numbers, Title Case headlines, humor in error copy ('Oops!'), em-dash crutch, one copy register per page.
development
Logged-in web apps — dashboards, auth flows, settings, onboarding, data tables, command palettes, modals, toasts. Register `product`: density and glance-speed over marketing polish, no hero/CTA-tricks, every data surface covers empty/loading/error explicitly, tables and dataviz follow preattentive-processing rules.
development
Marketing sites, landing pages, campaign pages — register `brand` (design IS the product). Structure comes from the register's POV + a macrostructure pick, never from copying an inspiration site's section flow. Hero discipline, deviated section order, asymmetric grids, and a silhouette lookalike-test gate before ship.
development
Token-strategy core — OKLCH color rules, neutral tinting, accent-commitment levels, type scale, 8pt spacing grid, touch targets, and the canonical output format of design-system.md (the file the harness gates on). This is routing step 1 of design-method/SKILL.md — read it before design-web/design-webapp/design-ios/design-android, before picking or auditing a single color/type/spacing value.