Agent SkillsPractical Guides
What Are Agent Skills? How They Differ from Prompts
Understand when a reusable Agent Skill is worth building, what belongs in SKILL.md, and when a normal prompt is enough.
2026/08/20
How to Test Whether an Agent Skill Actually Works
Evaluate trigger precision, output quality, failure behavior, context cost, and consistency with a compact test set.
A Skill is not reliable because one demo looked good. Test the conditions that are most likely to expose ambiguity.
Test trigger precision
Use one request that should trigger the Skill, one nearby request that should not, and one ambiguous request that requires clarification.
Test the output contract
Check required sections, file type, naming, citations, and validation results. Do not grade only tone or visual polish.
Test missing inputs
Remove one required input. A reliable Skill should request the missing value or follow a documented safe fallback—not invent it.
Test failure recovery
Simulate unavailable tools, unreachable sources, and invalid files. The Skill should report the limitation and preserve partial work.
Measure context and maintenance cost
Record which references are loaded by default and how often the Skill needs manual correction. A smaller predictable Skill often outperforms a broad one.
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Agent SkillsPractical Guides
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Build Your First Checkable Automation
Start with a task that has clear rules, stable inputs and a result you can inspect. A first automation could organize a test enquiry into a spreadsheet without automatically replying to the customer.
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Field notes
Get new Agent Skills, prompt patterns, and honest implementation notes. No fabricated metrics, no daily noise.