Include what the reader task requires
There is no useful universal percentage of a book to include in an AI skill. Start with one reader task. Keep the instructions and boundaries needed to perform it, make supporting examples and explanations available where they matter, and leave unrelated material outside that workflow.
The question is what each passage contributes. Does it change a decision, explain an exception, help the reader understand a result, or provide an artifact they need? Select material by that function before worrying about how short the package looks.
A concise skill can still be incomplete. A large source collection can still fail to explain the procedure. Neither length alone tells you whether the author's judgment is preserved.
Respect the different jobs a book performs
A book can persuade, explain, tell a story, document evidence, and teach a procedure. A skill supporting one task may need those elements at different moments.
Reader preferences also differ. In a discussion about business nonfiction, u/DameThistle wrote:
“TBF, I got good advice from many books, but after a certain point most of the new books started to be essentially the same advice, repackaged.”
That describes the commenter's experience with repeated advice across books, not proof that any particular manuscript is padded. Original comment.
In the same discussion, u/minimalist_coach offered a contrasting observation:
“It was always interesting to hear a client rave about a book I felt could have been summarized in 3 pages.”
The commenter's reported coaching background and client reaction are unverified. The useful point is modest: material one reader would shorten may matter to another. Original comment.
Do not use an audit to declare the book's stories worthless. Decide which belong in the working instructions, which should remain accessible as explanation, and which serve a different reading experience.
Give every passage one of four destinations
Use these editorial categories for the first pass:
| Decision | Meaning | Typical material |
|---|---|---|
| Keep | Put it in the active procedure because it governs the task | Steps, decision rules, required inputs, exceptions, stopping conditions |
| Move | Turn it into a separate usable artifact | Blank worksheet, completed form, checklist, reference table |
| Reference | Keep an accessible explanation or example and specify when to consult it | Detailed rationale, contrasting cases, deeper background |
| Omit | Leave it outside this skill's scope | Unrelated task, duplicate explanation, promotion for another offering |
“Omit” means omit from this task package, not delete from the book. “Reference” means give the material a clear role, not hide it in an undifferentiated folder.
The Agent Skills specification provides for main instructions, reference documentation, and assets such as templates. It recommends loading supporting resources as needed. These conventions support separating the procedure from supporting material; they do not guarantee a particular agent will choose or apply it correctly. Agent Skills specification.
Worked audit: one chapter about choosing a small experiment
Imagine a fictional practical book about improving a community newsletter. One chapter helps an editor choose a small change to try in the next issue. The skill's task is to produce a draft experiment plan from the editor's question and available observations.
This audit is an invented editorial example, not a customer conversion or a tested model result.
| Chapter material | Decision | Reason and destination |
|---|---|---|
| Opening story about an editor feeling overwhelmed | Reference | Useful motivation, but not required at every decision; offer when explaining the method's purpose |
| Rule: state one change and what you hope to learn | Keep | Governs every plan and prevents combining unrelated changes |
| Instruction to distinguish observations from guesses | Keep | Prevents presenting an assumed reader problem as established evidence |
| Blank experiment-planning sheet | Move | Becomes the reusable output template |
| Completed example comparing two subject-line approaches | Reference | Consult when the editor needs an example of a bounded question; do not copy its conclusion into another context |
| Exception: too little feedback to interpret the result confidently | Keep | Changes what the plan may claim and what follow-up is needed |
| Long history of the newsletter's founding | Omit | Not needed for this task unless a specific passage explains a governing constraint |
| Invitation to a separate workshop on sponsorship | Omit | A different task and commercial offer |
The selected material is smaller than the chapter, but the important uncertainty remains. Removing the exception to make the instructions shorter would weaken the method.
The template should preserve that uncertainty too: proposed change, question, existing observations, missing information, and how the editor will review the result. Do not label the last field “proof of success” if the method only supports a tentative interpretation.
Check what the shortened version can no longer explain
Take one straightforward case and one exception. Using the selected material, trace each significant decision back to its source. Ask what would go wrong if a referenced explanation were never opened.
If the missing material changes the decision, put the essential rule into the procedure. If it only expands the rationale, keep the reference and give a specific trigger for consulting it. “Read the uncertainty example when the reader has only one piece of feedback” is more useful than “consult resources as needed.”
Keep the manuscript location beside each extracted rule during authoring. When the book changes, that record helps you find the affected instruction or template. Mark interpretations you added yourself for author review rather than presenting them as direct extracts.
The guide to writing better agent skills covers broader instruction clarity. Your manuscript audit comes first: clear wording cannot repair a missing condition or an unsupported rule.
Stop cutting when the task loses its reasoning
The finished package should explain what information is needed, how the method uses it, what the reader receives, and when the procedure must pause. Supporting material should be findable for a clear reason.
After that editorial check, run representative scenarios in the intended environment and inspect the actual behavior. A tidy audit is preparation for testing, not evidence of successful execution.
To discuss your own book-to-skill scope, bring one chapter, a reader task, and a completed four-way audit to Skillfully. Choose Book onboarding with those materials ready.