Fletcher: Own All the Numbers Agent Skill

Defamiliarization audit for empirical output.

Context cost
2.4k tokensestimated from the bundle, loaded when it triggers
Bundle
1 file · 9.6 kBtext throughout, nothing executable
Licence
Source-availablethe author’s own terms
Last change
—no release on file
Servers it uses
Noneruns standalone

What it does

Defamiliarization audit for empirical output. Systematically interrogates every feature of a figure, table, or set of results — not just the main finding. Named for Jason Fletcher, who asked about the spike at t=1 when everyone else was looking at t=2. Use when you have output and are about to interpret or report it.

What this skill changes about the agent has not been set out here as a list. Its SKILL.md, shown below, says it in the author’s own words.

data science
Filed under

Research

The skill itself

A skill is instructions the model reads, so you can see what you are getting: below is the start of its SKILL.md. The front matter loads with every session, the body loads when the skill triggers, and the whole file comes with the install.

SKILL.md9.6 kB · preview
--- name: fletcher allowed-tools: Read, Bash(ls*), Bash(cat*), Glob, Grep argument-hint: "[path-to-figure, table, or results file] [brief description of what you think the main finding is]" ---
8# Fletcher: Own All the Numbers
9
10You are **Fletcher** — not an adversary, not a health inspector, but a mentor leaning over your shoulder at the moment you first see your output.
11
12Your model is Jason Fletcher, who described his practice as something learned from his own graduate training — the habit of reviewing output by stepping back from the main coefficient and asking about something else in the table: an odd pattern, an unexpected sign, a sample size that didn't add up.
13
14More often than you'd like to admit, that question mattered.
15
16The Viktor Shklovsky principle applies here: habit makes perception automatic. You stop seeing your output because you've already decided what it means before you looked. The purpose of this audit is to defamiliarize — to make you see the figure as a stranger would, before the story you want to tell has collapsed everything else into background noise.
17
18This is not referee2. Referee2 asks: *is this implemented correctly?* Fletcher asks: *do you understand what you're looking at?*
19
20---
21
22## Fletcher and Referee 2: Complements, Not Substitutes
23
24**Both should be run. Neither replaces the other.**
25
26| | Fletcher | Referee 2 |
This is a preview of SKILL.md. Download or install the skill to get the whole thing.
In the file
SKILL.md1,611 words
Files1
LicenceSource-available
Why you can read it

Nothing in a skill executes. The client loads the text and the model follows it, so a skill can be audited the way a runbook is — by reading it.

What it costs in context

Skills are not billed by the call. They are paid for in context: every token the instructions occupy is a token your code, your diff and your conversation cannot use. Here is what this one takes and when it takes it.

≈130
always loaded
The name and description, so the model knows the skill exists and when to reach for it.
2,270
on trigger
The instruction body, read only when the skill fires.
1.2%
of a 200k window
Ten skills this size would take about 12% of the window before you open a file.
050k100k150k200k context window

2.4k tokens, estimated from the bundle at four bytes to the token, held for the rest of the session once it triggers. Middling. Fine to keep on in a project where you use it weekly, worth unloading in one where you never do.

Servers bill, skills cost

A server charges by the month. A skill charges once per session, in context, and then keeps charging it for as long as the session lives.

Before and after

The same question, put to the same model twice: once as it comes, and once with these instructions loaded.

No worked example has been published for this skill yet.

The procedure it runs

The procedure has not been set out here step by step. It is in the body of its SKILL.md: the start of it is shown above, and the whole file comes with the install.

Prose, not code

These steps are written for a model to follow, not executed by a runtime. It can still be told to skip one, and it will say so when it does.

Servers it uses

None. This skill calls no MCP servers at all.

Everything it needs is in the instructions, so it works in a project with nothing connected — the model reads the file and changes how it works with what it can already reach.

Its SKILL.md asks for Bash, which can write files and reach the network alike, so what it touches is whatever the instructions themselves ask for — read them before you install it.

What it asks for
Writes filesnot declared
Network accessnot declared

The allowed-tools line of this skill’s own SKILL.md asks for Bash, which could do either, so neither is ruled out. A skill grants no permissions of its own — it can only ask for tools your client already has.

What it will not do

Every skill is narrow, and the useful ones say where they stop. These are the jobs this one is the wrong tool for.

What this skill is not for has not been published here. Nothing is implied by that: it is a section the author has not filled in.

What is in the bundle

1 file, 9.6 kB on disk. A bundle is text throughout: the instructions the model reads, plus the templates it fills in.

  • SKILL.md9.6 kB
What is not in it

No dependencies and nothing executable: a skill is text the agent reads, so the bundle is 1 file you can review in full before installing. The Source-available licence covers the templates and examples as well as the instructions.

Install

Installing copies the bundle into your project. Nothing runs at install time — the files sit on disk until the model reads them.

# Fletcher: Own All the Numbers · 2.4k tokens when loaded · macOS, Linux mkdir -p .claude/skills && t=$(mktemp -d) && curl -fsSL -o "$t/bundle.tar.gz" https://mcprush.com/api/skills/fletcher-own-all-the-numbers/bundle.tar.gz && tar -xzf "$t/bundle.tar.gz" -C "$t" && [ -d "$t/fletcher-own-all-the-numbers" ] && { [ ! -e .claude/skills/fletcher-own-all-the-numbers ] || { mv .claude/skills/fletcher-own-all-the-numbers "$t/.previous" && echo "Previous copy moved to $t/.previous"; }; } && mv "$t/fletcher-own-all-the-numbers" .claude/skills/ && echo "Installed .claude/skills/fletcher-own-all-the-numbers"
On Windows, or any OS with Node 20+
npx mcprush@latest skill add brycewang-stanford/fletcher-own-all-the-numbers

Windows PowerShell says 'running scripts is disabled on this system'? Run Set-ExecutionPolicy -Scope CurrentUser RemoteSigned once, or type npx.cmd instead of npx (codex.cmd, gemini.cmd, grok.cmd likewise). PowerShell 7 needs neither. Writes to .claude/skills/fletcher-own-all-the-numbers/ in the current project. For every project instead, run mkdir -p ~/.claude/skills && t=$(mktemp -d) && curl -fsSL -o "$t/bundle.tar.gz" https://mcprush.com/api/skills/fletcher-own-all-the-numbers/bundle.tar.gz && tar -xzf "$t/bundle.tar.gz" -C "$t" && [ -d "$t/fletcher-own-all-the-numbers" ] && { [ ! -e ~/.claude/skills/fletcher-own-all-the-numbers ] || { mv ~/.claude/skills/fletcher-own-all-the-numbers "$t/.previous" && echo "Previous copy moved to $t/.previous"; }; } && mv "$t/fletcher-own-all-the-numbers" ~/.claude/skills/ && echo "Installed ~/.claude/skills/fletcher-own-all-the-numbers" (macOS, Linux) — or add --global to the npx line. The curl line replaces .claude/skills/fletcher-own-all-the-numbers/ only after the download succeeds, so files left there by another skill of the same name, or by an older release, do not mix in. A copy already there is moved aside, not deleted, and the line prints where. It appears as fletcher in Gemini CLI, Codex, Copilot and Grok (its own name); Claude Code lists it by the folder name, fletcher-own-all-the-numbers.

Which clients pick it up on their own

A skill is a folder of text. Most of these read a skills folder and pick it up without being told; the rest take the same folder another way — an upload in the app, a parameter on an API call — and then choose it by its description just the same.

Claude Code.claude/skills/
Claude DesktopCustomize › Skills
ChatGPTSkills › Create › Upload
Cursor.cursor/skills/
VS Code.github/skills/
Codex CLI.agents/skills/
Gemini CLI.gemini/skills/
Grok Build.grok/skills/
Microsoft CopilotSkills › Upload a skill
PerplexityComputer › Skills › Upload a skill
DeepSeek Harness.dsh/skills/
Zed.agents/skills/
Devin Desktop.devin/skills/
Windsurf (legacy).windsurf/skills/
OpenAI Agents SDKInstructions or sandbox Skills
HTTP / APIa request parameter
This release
Versionnot versioned
Publishedno release date on file
PriceFree
Referencebrycewang-stanford/fletcher-own-all-the-numbers

Versions

Its author publishes no version number, so there is nothing here to pin to: what you install is the folder as it stands today. Instructions change more often than APIs do — a skill can be rewritten entirely without anything it depends on moving.

Pinning

Nothing to pin to: this skill carries no version number of its own. What you install is what the folder holds on the day you install it.

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