Skill vs prompt
A good prompt and a good Skill can look identical on one successful run. They diverge on the second run, and on the hundredth.
Short version
A prompt is text you send for one task. A Skill is a packaged procedure that an agent can discover, activate when the task matches, and reuse indefinitely.
The functional difference is not length or quality. It is that a Skill carries a description the agent can see before activation. That single property is what turns instructions into something the system can select on its own.
If you have to paste it, it is a prompt. If the agent should find it on its own when the right task appears, it is a Skill.
Side by side
| Aspect | Prompt | Skill |
|---|---|---|
| Form | A block of instructions in one conversation | A folder with SKILL.md and optional assets |
| Selection | You decide when to paste it | Activated when the task matches its description |
| Visibility before use | None: the model sees it only when sent | Name and description are visible before activation |
| Reuse | Copy and paste again | Installed once, available to every matching task |
| Versioning | Wherever you happened to save the text | Files in a repository, reviewable and diffable |
| Extra assets | Usually none | References, scripts, and templates loaded on demand |
| Typical failure | It drifts as people edit their own copies | It never activates, because the description is too vague |
When a prompt should become a Skill
What a Skill adds to a prompt
A Skill is not a longer prompt. It changes four things at once.
The description states the conditions for activation, so selection stops depending on a human remembering to paste anything.
Long references stay out of the main file and load only when the workflow actually needs them.
Scripts handle the parts where a language model should not be improvising, such as parsing or validation.
Because it lives in version control, the procedure can be reviewed, tested, and improved instead of forking silently.
People often convert a prompt into a Skill by adding more words. The useful conversion is the opposite: write a precise activation description and move the bulk out into references.