Immutable. This exact content is served forever at /api/v1/blob/e4a6b2da9c7b7b2b.
---
name: ux-writing
description: "Judgment rules for user-facing text and docs: CLI and diagnostic output, error and help text, README and docs structure, code comments, titles, and generated reports, decks, or exports. Use when writing or changing any user-visible string, when adding or restructuring docs or deciding which page owns a fact, when a page is about to record a version, a deployment state, or a value the code already owns, when a comment, title, or artifact could carry the reasoning or an abandoned option behind the change, when a behavior change needs its copy sites swept, or when reviewing a diff that touches copy or docs."
license: Apache-2.0
metadata:
author: scarletkc
fogmoe-source: https://github.com/FogMoe/agents
fogmoe-summary: "Review user-facing copy and documentation for clarity, consistency, facts that do not go stale, and no leftover intermediate state."
---
# UX Writing & Docs
User-visible text is product behavior and carries the same quality bar as
code. Every rule below is distilled from a real defect caught in review, and
keeps its counter-example because the reasoning is the point. When in doubt,
re-read the output as the user who just hit the problem.
## Status output & diagnostics
- **Report effective values, not stored ones.** A status display answers
"what will happen when I run this", so resolve values exactly the way the
runtime does, including environment variables and layered config.
*Counter-example: a config viewer printed "API key set: no" while an env
var held the key the next run would actually use.*
- **Diagnostics must stay truthful under failure.** When one config layer
fails to load, fall back to the most complete state that still loads,
never to blank defaults. A diagnostic that misreports is worse than one
that aborts. *Counter-example: a broken project-level config made a doctor
command check blank defaults and report a missing API key that was in fact
configured; the fake failure buried the real one.*
- **Show deltas, not dumps.** A health/diagnostic command lists what
deviates and who set it; the exhaustive listing belongs to the dedicated
inspect command. Don't make one command duplicate another's job.
*Counter-example: a doctor check printed fifteen "field: origin" lines,
most of them saying "global". One line naming the two real overrides
replaced the block.*
- **Annotate at the granularity of the claim.** If one sub-part of a
composite value has a different source or state, say it on the sub-part;
don't relabel the whole. *Counter-example: an env-injected API key
relabeled an entire endpoint block "(environment)" although its URL and
model came from a file. The fix was "key from env", with the block label
unchanged.*
- **Re-read neighboring labels after adding metadata.** New suffixes collide
with existing value labels. *Counter-example: "Embedding dimensions:
default (default)", fixed by renaming the value "auto".*
- **Machine-readable output is a contract.** Porcelain/TSV/JSON output never
gains decoration, notices, or annotations; informational text goes to
stderr or the human-format path. Absence is part of the contract, so write
the negative test (`"(project)" not in stdout`).
- **Never truncate the payload.** Paths, IDs, and URLs in diagnostics must
survive narrow terminals un-ellipsized (disable auto-wrap/crop for those
lines); a truncated path cannot be copied into the next command.
## Error messages
Every error answers three questions: what happened, where, and what to do
now. The strongest pattern: name the offending file or input, list the
rejected fields, list the allowed fields, and say where the rejected setting
belongs instead. Fail loudly rather than degrade silently; when catching an
exception purely to suppress a traceback, keep the message intact.
## Documentation
- **Each document has one responsibility, and it decides what belongs.** A
page is a durable contract, a proposal, an investigation, a TODO, a dated
work order, or a runbook — one of them, not several. Naming that first is
what makes a canonical home decidable: a fact lives on the page whose job
it is, and every other surface reaches it through a single specific link
instead of a partial retelling on each page that happens to touch it. When
two pages both claim to be the detailed spec, the broader responsibility
keeps the shared rules and the narrower keeps only what its own surface
adds. *Counter-example: an implementation plan stayed the de-facto spec
after shipping, so the rules lived half there and half in the architecture
doc; folding the stable rules into the contract and leaving the sequence in
git history left one page to trust.*
- **Rationale is a genre of its own.** A how-to answers what to run, a
reference answers what exists, and why-it-was-built-this-way belongs to a
design record, an ADR, or the pull request that decided it. Answering the
design question inside a usage page pushes the steps the reader came for
below the fold, and the argument is also the part that rots first: the
implementation moves on and only the guide still defends the old choice.
An explanation produced because someone asked once belongs in that
answer, not in a permanent page. *Counter-example: a setup guide spent
its second paragraph on why this queue was chosen over two others; the
queue was replaced a release later and the paragraph outlived it.*
- **One canonical home per fact.** Details that change together (field
lists, precedence chains, supported values) live in exactly one document;
every other mention links to it. Legitimate copies: artifacts distributed
standalone (a bundled skill file that ships without the repo), and
genuinely surface-specific nuance. *Counter-example: a seven-field
allowlist pasted into five docs.*
- **Restating and linking is a bug, not thoroughness.** If a section
duplicates the canonical content and then ends with "see X for the full
contract", it already is the full contract. Delete the restatement; keep
the link and whatever is specific to this surface.
- **Prefer the smallest sufficient edit.** When revising existing text,
preserve unaffected wording, structure, and rationale. Remove genuine
duplication, but do not rewrite neighboring prose or compress away useful
distinctions without a reason. *Counter-example: changing one mandatory
workflow into an optional one rewrote several surrounding sections, then
over-corrected by removing useful context; a few local edits were enough.*
- **Insertion respects adjacency.** Before adding a section, check what the
surrounding paragraphs attach to. *Counter-example: a new section landed
between a flags table and its output-format footnote, orphaning the
footnote in the wrong chapter.*
- **Adjectives need evidence.** "Recommended", "faster", "better" come from
your own benchmarks, not optimism. *Counter-example: a feature was about
to ship commented "# recommended" while the project's own eval showed it
losing to the default on strong models. It shipped as "optional".*
- **Every README section has one job.** Positioning sections ("Why X?")
don't accumulate feature bullets; quick-starts don't explain architecture.
A README stays lean and links into the docs; detail accumulating there
usually means it left its canonical home.
- **Order a page by what the reader needs first, and split when it stops
being one task.** Open with scope and the authoritative entry points, then
the common rules and the main path, and only then exceptions, recovery,
and change checks. An overview layer summarizes stable semantics and links
down; it does not carry field tables, full payloads, or current numbers to
buy self-containment. When a page starts demanding that the reader
understand several unrelated tasks, or whole chapters serve only two
maintainers, that is the signal to split it — and the split leaves behind
one line of purpose plus the link, never a second copy of the fact.
*Counter-example: a getting-started page opened with the full option
reference, so the three commands a first-time reader needed sat two
screens below it.*
- **Reminders name the most-forgotten item only.** A guideline that
enumerates every artifact reads as noise and gets skipped whole. "Update
whichever docs the change affects; the bundled skill is the easiest to
forget" beats a list of six file types.
## Facts that go stale
Docs are edited on a human cadence, while some facts change on every commit,
deploy, or restart. Writing one of those into a long-lived page is not a
maintenance burden, it is a defect on a delay: the page turns wrong on its
own, and nothing fails when it does. Record where the current answer is
read, not the answer. This is "report effective values, not stored ones"
applied to prose.
- **Never snapshot a value that moves faster than the doc.** Long-lived
pages (README, architecture notes, runbooks, domain docs) carry the stable
material: intent, invariants, boundaries, procedures, failure handling.
Version and protocol numbers, image tags, build IDs, deployed commit
hashes, object and migration counts, expiry dates, and "currently live /
not yet shipped" claims all change without anyone re-reading the page that
repeats them. Those belong in a changelog, in git history, or on the
release ticket, where carrying a date is the point. The rule forbids the
hand-maintained second copy, not the table: when a page genuinely has to
show current values, generate it from the authoritative source at build
time so it cannot drift silently. *Counter-example: a
runbook opened with "production currently runs 2.3.1"; four releases later
an on-call engineer trusted the line and worked through the wrong
version's changelog.*
- **A pointer names a symbol, not a repository.** The canonical home for a
fact is often code rather than a doc, and then the doc's job is to say
where to read it instead of copying the value or the whole field table.
Make the pointer land: a specific file plus a searchable symbol, function,
data key, or heading. "See the source", a repo-root link, or a directory
leaves the reader to re-derive what the sentence promised. If no single
symbol owns the fact, that is a code problem surfacing as a doc problem;
fix the boundary instead of papering over it with a copied table. A
directory is a fair target in two cases only: the fact emerges from an
ordered set with no single-file truth (migrations replayed in sequence),
or the directory is a catalog some loader enumerates (locales, plugins,
maps). Both still owe a searchable selection key — the naming convention,
the loader function, the object name.
*Counter-example: "protocol versions are defined in the networking layer"
sent every reader grepping six files, and became a link to
`PROTOCOL_VERSION` in `net/constants.py`.*
- **A doc cannot observe the runtime.** The repository answers how a commit
is meant to behave; only the running system knows which commit is live,
what is healthy, and which artifact is being served. Docs record the
command or console that answers those questions, never the answer, and
never promote merged code to "deployed". A successful deploy report is
evidence on that release's ticket; copying it into a doc converts a
one-time result into a standing hand-sync obligation. *Counter-example: a
"current environment" table listing service versions was updated by hand
after every deploy, until the deploy where it wasn't, and nothing in CI
could notice.*
## The final state, not the path to it
A deliverable is read by someone who was not in the room while it was made.
Anything that only holds against the conversation behind it — an option
that was considered and dropped, a scope that was corrected, an instruction
the requester gave ten minutes ago — reads as noise at best, and at worst
as a claim about the product. Session context expires faster than the
artifact carrying it, so this is "facts that go stale" applied to the
conversation rather than to time. The test for any line: does it hold for a
reader who has never seen that conversation? "Without the bulk-download
panel" does not, because nobody expected one. "Not `json.dumps` here, the
payload has to keep key order for the signature check" does.
- **State what the code does, not what it nearly did.** Titles, summaries,
and comments describe the shipped behavior; intermediate attempts,
abandoned options, and negative scope belong to the discussion that
produced them, which git history and the review thread already keep.
*Counter-example: a requested cut left the pull request titled "Add
export button (without the bulk-download panel)", so every reader had to
understand a panel that never existed before reading the one that did.*
- **A comment carries the non-obvious reason only.** What earns the lines
is a constraint the next reader cannot recover from the code: an ordering
requirement, an upstream bug, a platform quirk. A "why not X" line
qualifies when X is what that reader would reach for anyway, not when X
is merely what this conversation happened to try and discard. Restating
what the code plainly says, or defending it against an alternative nobody
would propose, spends attention now and becomes a lie when the code
around it moves. *Counter-example: a helper kept eight lines on why it
held no cache, written the moment a reviewer asked for the cache to go;
two rewrites later the paragraph was the only trace of either.*
- **Evidence serves the reader's decision, not the author's doubt.** A
claim the reader has to act on — this one is faster, this default is
safe, use this over that — owes its basis, and "adjectives need evidence"
above says where the basis comes from. A statement of what the code does
owes nothing, because nobody is being asked to believe anything: a cited
standard, a benchmark number, or an appeal to consensus attached to it is
answering a challenge that was never made. The test is whether removing
the line changes what the reader can decide. Cited figures also age
faster than the sentence carrying them, and nobody comes back to
re-measure. *Counter-example: a config page defended its default with
"benchmarks show a 40% improvement", measured two majors earlier against
a code path that no longer existed; support was still quoting the
number.*
- **A deliverable does not narrate its own production.** Generated reports,
decks, exports, and screens are product content: they carry findings,
values, and instructions, never the implementation notes, method
rationale, or next steps of whoever produced them. "This page
demonstrates", "we could also", and "implemented as" are the producer's
voice leaking into the product, and the exceptions are narrow — copy that
genuinely is help text or an empty state, and documents explicitly asked
to record their own methodology. Reasoning has its own homes: the reply
to the requester, the commit message, the pull request body, a planning
file. *Counter-example: a generated status deck opened on a slide titled
"Approach and next steps for this report", ahead of the numbers it had
been asked for.*
## Sync sweep for behavior changes
A behavior change is unfinished until its copy sites agree. Grep for the old
wording across, in rough order of forgettability:
1. `--help` option strings, the most-missed site: a flag's help kept saying
"show current configuration" after the command learned origin labels,
2. centralized message/string modules and command docstrings,
3. README and docs pages,
4. bundled skill files, plugin metadata, MCP tool descriptions (these are UX
for agents, and the same rules apply),
5. roadmap or status notes describing the old behavior.
Then re-resolve the links involved: a renamed heading breaks every anchor
aimed at it, a moved file breaks the relative paths pointing at it, and
neither announces itself in a normal test run.
## Testing copy
- Assert flattened text or behavior, not console formatting: consoles wrap
(~80 columns under test runners), so multi-word substrings split across
lines. Flatten with `" ".join(output.split())` before substring
assertions.
- Color env leakage: `FORCE_COLOR` / `COLORTERM` in the invoking shell make
rich consoles emit ANSI into captured output; clear them for test runs.
- For machine formats, assert what must be absent, not only what must be
present.