Turn instructions into a skill
A portable skill contains a SKILL.md with name and description metadata plus the working instructions. References, templates or scripts can be added. The description explains when to use it; the instructions explain how. Check the documented import route for the Claude interface rather than treating an arbitrary text document as an installed skill.
Example: recurring proposal review
The skill receives approved requirements and a proposal. It creates a fixed list of fulfilled points, uncertainties and questions with references. One test uses a complete proposal; another omits the service description. The owner checks that missing information remains visible and the AI invents no commitments. Record changes to the template and skill together.
A skill does not grant blanket permissions
A third-party skill package can contain executable code and additional dependencies. Review them before enabling it. Credentials do not belong in its files. Bound required connections and external actions separately. Good instructions replace neither control of the tools nor a test for unintended use outside the skill’s scope.
Decision matrix
| Decision point | Proceed when | Stop when |
|---|---|---|
| Assignment and inputs | Documented: a clear goal, permitted inputs, rules, review and output format. | Scope, data or accountability remains unresolved. |
| Repeatability | Evidence consists of recorded runs with suitable, incomplete and disallowed inputs. The output meets the agreed format and makes missing information and boundaries visible instead of filling gaps. | There is only an unevaluated demo without acceptance evidence. |
| Maintenance and boundaries | Owner, approval, fallback and next review date are defined. | Avoid: overly broad tasks and missing test cases. A skill is only reviewable when its goal and expected output are narrow enough for a domain reviewer to accept an individual run. |
Keep it verifiable
Primary sources
- Anthropic: How to create custom skillsSource checked:
- Agent Skills: SpecificationSource checked:
