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Nobody went to law school to count words. Yet somebody in your office, probably the most junior person available, is checking whether the brief is in 14 point, whether the margins are an inch, whether the certificate of compliance says the right thing, and whether the circuit you are filing in has quietly kept the old word limit.
This is the most automatable work in litigation. It is also, in most firms, the least automated, because the rules differ enough between courts that no off-the-shelf tool covers yours.
Why this is genuinely hard
The difficulty is not that any single rule is complicated. It is that the rules stack, and each layer can override the one above it.
Take a federal appellate brief in the United States. FRAP 32 gives you the general form: a proportionally spaced typeface of 14 point or larger, or a monospaced face of no more than 10.5 characters per inch, margins of at least one inch on all four sides, and double spaced body text. Rule 32(a)(7) sets the type-volume limit: 13,000 words for a principal brief, 6,500 for a reply, with a certificate of compliance required unless the brief comes in under 30 pages, or 15 for a reply.
So far, encodable. Then comes the part that catches people out: several circuits amended their local rules specifically to keep the longer pre-amendment word limits. The number in the federal rule is not necessarily the number that governs your filing. Then a judge's standing order can tighten it again.
Three layers, any of which can move, and a rejected filing at the bottom.
Two courts, two worlds
We work across US and Indian practice, and putting the two side by side shows why a generic "format my brief" prompt is useless.
The US federal appellate position, above: 14 point proportional, double spaced, one inch margins, 13,000 words, certificate of compliance.
The Supreme Court of India, by circular, specifies something with no overlap at all. Superior quality A4 paper of not less than 75 GSM, printed on both sides. Times New Roman, font size 14, at one and a half line spacing. Quotations and indents drop to size 12 at single spacing. Margins of 4 cm left and right, 2 cm top and bottom. Where a filing runs to more than one volume, a common index goes in the first volume and a separate index in each.
Two courts. Different paper, different spacing, different margins, a different unit of measurement, and one of them cares whether you print on both sides.
A lawyer holding both rule sets in their head is doing work a text file should be doing.
What a skill is
A skill is a folder with a SKILL.md file in it. That file is markdown with YAML frontmatter at the top and instructions in the body. That is the whole format.
Only two frontmatter fields are required: name, which must match the folder name, and description. There are optional ones, including allowed-tools, compatibility, license and metadata.
The mechanism worth understanding is how a skill gets picked up. Claude reads the description and matches it against what you have asked for. If it matches, the body loads and Claude follows it. If it does not, the skill stays dormant and costs you nothing.
Which means the description is not a summary for humans. It is the trigger. Write it as the conditions under which this skill should fire, in the words you would actually use.
Writing the skill
Four things separate a formatting skill that works from one that produces plausible nonsense.
Put numbers in, not prose. "Use an appropriate font size" is worthless. "Body text: 14 point Times New Roman" is a rule. Anything a machine cannot check, a machine will guess at.
State the override order explicitly. The skill has to know that the local rule beats the federal rule and the standing order beats both. Write that hierarchy down, and tell it to stop and ask when it cannot tell which applies.
Tell it what it may not decide. This is the part people skip. A formatting skill should never be choosing whether an argument fits the word limit by cutting the argument. Draw that line in the skill body: it may flag that you are 400 words over, it may not decide which 400 words go.
Date it. A line saying when the rules were last checked, right in the body. Formatting skills go stale silently, and a stale skill is worse than none because it is trusted.
A working example
Here is a real one, trimmed. Folder ca9-brief, file SKILL.md:
---
name: ca9-brief
description: Format and check a brief for filing in the US Court of Appeals
for the Ninth Circuit. Use when asked to format a Ninth Circuit brief,
check type-volume compliance, verify a certificate of compliance, or
confirm whether a CA9 brief is within the word limit.
---
# Ninth Circuit brief formatting
Rules checked: 12 September 2026. Re-verify local rules before relying
on the limits below.
## Order of authority
1. A standing order of the panel or judge, if one exists
2. Ninth Circuit local rules
3. FRAP
If you cannot determine whether a standing order applies, STOP and ask.
Never assume FRAP governs.
## Form (FRAP 32(a))
- Typeface: proportionally spaced, 14 point minimum
- Alternative: monospaced, max 10.5 characters per inch
- Margins: minimum 1 inch, all four sides
- Body text: double spaced
- Headings and footnotes may be single spaced
## Type-volume (FRAP 32(a)(7))
- Principal brief: 13,000 words
- Reply brief: 6,500 words
- Confirm against the current CA9 local rule before reporting compliance.
Several circuits retained higher pre-amendment limits.
- Certificate of compliance required unless the principal brief is
30 pages or fewer, or the reply is 15 pages or fewer.
## Counting
Count the words that the rule counts. Exclude the corporate disclosure
statement, tables of contents and authorities, certificate of compliance,
certificate of service, and any addendum. State which exclusions you
applied.
## What you must not do
- Do not cut, compress or reword argument to fit the limit. Report the
overage and its size. The lawyer decides what goes.
- Do not draft the certificate of compliance content from assumption.
Use the measured count.
- Do not report "compliant" if you could not verify the current local
rule. Report "compliant with FRAP, local rule unverified".
## Output
Always end with a table: rule, requirement, what this document does,
pass or fail. Then the measured word count and the exclusions applied.Roughly sixty lines, written once. Every Ninth Circuit brief after that is formatted the same way by the same rules, and arrives with its own checkable audit trail.
One skill or many
Build one per court, and split further by document type where the rules genuinely differ.
The temptation is a single court-formatting skill with a lookup table covering everywhere you file. Do not. That design forces Claude to reason about which court's rules apply before applying them, and that reasoning step is exactly where it will hand you the Second Circuit's word limit for a Ninth Circuit brief. It fails quietly and plausibly, which is the worst way for anything to fail.
Separate skills fail loudly instead. Ask for a Ninth Circuit brief with only a sci-slp skill installed and nothing triggers. You notice immediately.
Start with the two courts you file in most. That is usually eighty per cent of the volume.
The compliance check
The output table is not decoration. It is the reason this is safe to use.
A skill that silently returns a formatted document asks you to trust it. A skill that returns the document plus a rule-by-rule table of what it applied, the count it measured and the exclusions it took, lets a human verify the whole thing in about fifteen seconds. That is a real review, not a rubber stamp, and it is fast enough that people will actually do it.
Anything a skill cannot verify, it should say it cannot verify. The line "compliant with FRAP, local rule unverified" is worth more than a confident green tick, because it tells you precisely where to look.
Keeping it current
Rules change. Word limits get amended. Circuits adopt and drop local overrides. A court issues a circular about paper weight.
Two habits are enough:
- The date line in the skill body, treated as an expiry rather than a footnote.
- A quarterly review of every formatting skill, plus an immediate one whenever a court publishes an amendment in an area you file in. This is a sensible thing to put on a recurring schedule.
A skill is a written-down rule that stops being your problem to remember. It is only worth having if the written-down rule is right, and keeping it right is a fifteen minute job four times a year.
If you would rather have these built and maintained for the courts you actually file in, that is part of what we do.