A reusable method can live in a file instead of being explained from scratch each time. The Agent Skills format defines a folder with at least a SKILL.md file. Moving that package and obtaining the intended behaviour are separate outcomes.
Separate the method from the input
Consider an original example that organises product notes into features, conditions and open questions. Product facts change between runs; the categories and the rule against inventing unknowns remain. Write those stable instructions first.
Know what the package carries
The specification combines metadata with Markdown instructions and optional scripts, references and assets. It does not carry an entire chat history. A skill that depends on external tools also needs corresponding access in the destination app.
Test conditions, not identical wording
Use input containing a missing price, an uncertain date and a confirmed feature. Check whether both applications preserve uncertainty and sort the feature correctly. Change one instruction and run the check again. Word-for-word output identity is not the goal.
Milo’s assessment
Let’s put the options side by side. The method travels; environment capabilities remain a separate question. A small meaningful test distinguishes package acceptance from correct operation.
