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Files and documents — Cowork's bread and butter

How to specify Word, Excel, PowerPoint and PDF outputs that come out usable on the first pass. The four formats that matter, plus multi-file and versioning patterns.

Updated 2026-04-25Read 6 min

TL;DR. Cowork ships Word, Excel, PowerPoint, and PDF as first-class outputs — no copy-paste from a chat window required. Most "Cowork's outputs are bad" complaints come from prompts that did not specify formatting. This page is the cure: a small spec per format, copy-paste ready.

The four output formats that matter most#

  • Word (.docx) — narrative documents, briefs, summaries, anything someone will read.
  • Excel (.xlsx) — financial models, trackers, reconciliations, anything someone will calculate against.
  • PowerPoint (.pptx) — internal decks, status updates, anything someone will present.
  • PDF — final-form artifacts, signed-off versions, anything someone will share externally.

Most teams need three of the four every week. Cowork generates them directly using its own tooling — it does not click around inside Office. That means the output is consistent across operators and reproducible across runs.

How to specify Word output#

Always specify four things: voice, length, section headings, and whether to include a table of contents.

Write a one-page brief in ~/output/q2-brief.docx.
Voice: British English, no marketing language.
Length: 400–500 words.
Headings: H1 title, H2 for each of: situation, options, recommendation.
No TOC. No cover page.
Source: ~/inbox/q2-data.xlsx and ~/inbox/q2-context.md.

Common failure: vague "make it short." Cowork will define short for you. Define the word count.

How to specify Excel output#

Always specify five things: column headers, freeze panes, sheet names, formula references, and where totals go.

Build a reconciliation workbook at ~/output/recon-2026-04.xlsx.
Sheets: TB, Bank, AR, AP, Reconciling.
TB sheet: columns Account, Debit, Credit, Balance. Headers in row 1; freeze top row.
Reconciling sheet: any row whose absolute difference exceeds £500.
Totals: bottom of each sheet, formula references — never paste values.
No merged cells anywhere.

Common failure: getting back merged cells. Tell Cowork "no merged cells" explicitly. Add it to CLAUDE.md once and forget about it.

How to specify PowerPoint output#

Always specify four things: slide count, layout, template, and speaker-notes density.

Build a 5-slide internal update at ~/output/ops-update.pptx.
Slide 1: title + subtitle. Slides 2–4: title + 3-bullet content, max 25 words per slide.
Slide 5: next steps with owners.
Speaker notes: 2–3 sentences per slide, written for the presenter.
No template — use Cowork's default. We'll re-theme manually.

Common failure: word-heavy slides. Cap words per slide explicitly. Twenty-five is a defensible default; thirty-five if your audience reads while you talk.

How to specify PDF output#

PDFs are generated from content. If you want a designed PDF — proper typography, logo, the works — write a Word doc first, then export to PDF outside Cowork.

Tinkso convention:

  • Drafts in .docx
  • Finals in .pdf
  • Archive both

That convention plays well with versioning (next section) and means PDFs are always produced after sign-off, not before.

Multi-file workflows#

Three rules for any operation that touches more than a handful of files:

  • Tell Cowork the source folder and the destination folder explicitly. Implicit paths produce surprises.
  • Use plan-mode for any operation across more than five files. Read the plan; push back; approve.
  • Ask for a manifest file — a markdown index of what was created, where, and what each output covers.

The manifest is the audit trail. Operators can scan it in 30 seconds and decide what needs review.

Versioning patterns#

The Tinkso default that survives across engagements:

  • Filenames end in _v1, _v2, _v3. Never overwrite.
  • Encode the rule in CLAUDE.md so every operator follows it.
  • Move retired versions into archive/ once a month.

This costs almost nothing and prevents the "who deleted the working copy?" moment that ends Cowork honeymoons.

Tinkso's take#

The single largest quality gap we see is in PowerPoint outputs. Out of the box, Cowork makes word-heavy slides because that is what most of its training corpus contains. The fix is in CLAUDE.md house style: cap words per slide and require speaker notes. Set this once and the team's decks improve overnight.

The second-largest gap is operators who skip the format spec — "just make me a Word doc" — and then complain about the result. Treat the format spec the way you would treat a brief to a junior analyst: the more precise the brief, the less rework.

Try this#

Give Cowork a 4-page PDF and ask it to produce a 3-slide deck plus a 1-page Word brief. If the deck is wordy, look at your prompt before you blame the model — the discipline is in the spec, not the inference.

Need help applying this?

Book a 30-minute call. We'll ask where you are, what your team needs, and which systems Cowork should touch.

Last reviewed: 25 April 2026 · The Cowork Bible · Tinkso