These three words get used interchangeably in AI marketplaces, and that's the actual source of confusion. A Skill, a Prompt Pack, and an Agent solve the same category of problem in three structurally different ways. Picking the wrong one means either overpaying for automation you didn't need, or underbuying a tool that can't finish the job.
The one-line version
A Skill teaches Claude a specialist's judgment for an ongoing conversation. A Prompt Pack gives you a proven instruction you copy into your own AI account for a single task. An Agent runs the whole job end to end and hands you a finished result.
A concrete example: publishing on Amazon KDP
Say you're launching a book on Amazon KDP. Here's how the same problem looks under each model.
The Skill version is something like a "KDP Royalty Calculator" you load into Claude once and reuse for every future pricing decision, an ongoing tool that lives in your account.
The Prompt Pack version is a "KDP Prompts" library, a set of proven instructions for writing your book description, choosing categories, and drafting your author bio, that you paste into whichever AI account you already use.
The Agent version is a "KDP Launch Agent" you hand your manuscript to, and it comes back with a finished listing: description, keywords, categories, and pricing recommendation, done, not drafted.
Skill: judgment you keep
Loads once, then applies a real consultant's checklist to every WordPress SEO question you bring to Claude from that point on.
See Wanda →Prompt Pack: one proven instruction, any AI account
No account to link, just copy the prompt into Claude, ChatGPT, or whichever AI you already use, and run it for this one project.
See the prompt →Agent: hand it off, get a finished result
Give it the multi-step task and it works through the full sequence on its own, inbox triage, scheduling, follow-ups, and returns the finished result rather than a draft.
See William →How to actually decide
Ask whether you'll face this exact type of decision again next month. If yes, a Skill is worth loading once and keeping. If it's a single task you need done today in whatever AI account you already have open, a Prompt Pack is the cheaper and faster fit. If the task has multiple steps and you want the finished output rather than a draft you still have to assemble, that's what an Agent is for.
FAQ
Can a Prompt Pack do what a Skill does? For a single use, yes. What it doesn't do is persist as reusable judgment across every future conversation the way a loaded Skill does.
Do Agents replace Skills? No, they solve different shapes of problem. A Skill is judgment you apply yourself, an Agent is a full task delegated end to end.
Which one should a beginner start with? A Prompt Pack, since it needs no setup and works in whatever AI account you already use.