Prompting is the worst way to use Claude. Use CFO Skills
Anthropic's own finance team built 70 skills. Here is what top CFOs know that you don't.
The CFOs getting real value from Claude are not writing better prompts.
They stopped writing prompts almost entirely. They build skills and workflows. You teach Claude once, and then they run in the same disciplined way every single time.
Anthropic went from $9 billion to over $30 billion in revenue in just 4 months.
Krishna Rao is the CFO who runs the finance function behind that number. On the Invest Like the Best podcast, he talked about how his team uses Claude Skills to do their own monthly close.
The numbers he gave are remarkable.
Statutory financial statements for all of Anthropic’s legal entities are now produced using Claude. A human checks the output. Claude does the work.
The team has built a library of finance-specific skills, more than 70 of them at last count, sitting in a shared repository that everyone can access.
On top of that library, they built one skill called MFR. The monthly financial review skill. Krishna’s quote on it.
It can produce our monthly financial review. It’s 90 to 95% ready and then all of our discussion becomes about what do we do, what are the implications, not what exactly happened. Because Claude is not just reporting the weather. It’s also helping to think about drivers and why the number changed the way it did.
A weekly revenue or compute utilization report that used to take hours now takes 30 minutes. The biggest internal Claude user inside the finance team is not the 22-year-old who joined with a coding background. It is the head of tax.
That is what the closed-loop MFR looks like when it works.
Every CFO can build a version of it.
One MFR skill installed inside Claude. It reads the actuals. It surfaces the signals. It builds the visual reasoning. Then it refuses to produce the deck until the CFO answers four guided questions, each grounded in the evidence the skill built first.
Krishna’s MFR skill is built on Anthropic’s books.
You can build on your books.
When you just chat, you start from nothing every time
Always start with Claude projects, then skills.
Go to claude.ai.
Click Projects on the left, then click New Project.
Projects
A Project holds your context for good. Your company facts, your data dictionary, how you define net revenue, what counts as returns, your fiscal calendar. Claude reads all of it with every prompt, so you never re-teach it what your company is. This is also where you park the rule. Cite every number, or flag it.
Skills
Open the skill manager in Claude and Upload your skills.
A Skill runs a task the same way every time. Your monthly variance commentary. Your reforecast. Your board brief. You build it once, and Claude pulls it on its own when the work calls for it.
For example, the variance skill reads the 24-month P&L, reconciles the revenue, dissects the trade promotion, recomputes every figure in code, and hands back board-ready commentary with each number tied to its source. It does in one pass what used to take you an afternoon of copy-paste and chain-of-thought prompting.
Using projects and skills, CFOs would get accurate results.
Claude Masterclass for CFOs Who Want to Build CFO Skill Stack (LIVE)
We are hosting a private Claude Masterclass for CFOs on Thursday, July 16, at 11:00 AM ET.
This is not a demo. This is a 60-minute, hands-on walkthrough of how to build the one thing that separates CFOs getting real value from Claude and the ones still typing prompts into a chat box. Skills.
Live. Ask questions. Challenge what works and what does not.
Here is what most CFOs still do not understand about Claude.
The CFOs getting the biggest results are not writing better prompts. They are building skills. A skill is a workflow you teach Claude once that then runs the same disciplined way every single time.
Every CFO reading this knows the moment arrived. The question is no longer whether to learn Claude. It is how fast.
What I will cover
The AI foundation most CFOs skip
Why every CFO must use Project for any serious finance work.
The one instruction that makes Claude’s output safe for a board.
How to set up a Project so Claude holds your company’s numbers and rules every time.
How to build a skill from scratch
Building a monthly financial review skill live, start to finish.
What a skill actually is, in plain terms, and why it beats a prompt.
How to turn one working skill into a library your whole team can run.
How a skill forces Claude through the same steps every time: inventory the inputs, flag the exceptions, check its own math, and write the summary.
The skills every finance function must own
Monthly close and variance commentary.
Board pack assembly and narrative.
Cash flow forecasting and scenario work.
The strategic layer
What to build this quarter and what to wait on.
Where skills save real time and where they do not.
How to make your finance function AI-native without losing the audit trail.
Who this is for
CFOs, VPs of Finance, FP&A leaders, and controllers. Anyone running a finance function that needs to be ready for what comes next.
What to expect
A 60-minute live masterclass. I will build skills in my actual Claude environment, from a blank Project to a working skill library, and you will leave knowing how to build your own. Open Q&A throughout. Honest discussion of what works and what breaks.
As a paid member, you get full access to all written content.
Live masterclasses are exclusive to Insider members.
If you want the live experience, upgrade to Insider. If you are already an Insider member, the registration link is below.