writing-simplified-technical-english

A plain-writing rulebook borrowed from aircraft maintenance manuals (short sentences, one meaning per word, active voice), applied to whatever an AI assistant writes for people to act on, so it cannot be misread.

WHEN TO USE

SCOPE

USE FOR

Write a findings report or summary that someone can act on without reading it twice.
Keep pull request descriptions, commit messages and code comments short and unambiguous.
Write instructions or prompts for another AI agent with one instruction per sentence.
Rewrite a dense draft sentence by sentence while keeping every number and condition in it.
Word error messages, empty screens and log lines so the reader knows what to do next.

NOT FOR

Marketing copy, blog posts or anything persuasive, where the writer's voice is the point.
Quoted text from a user, a log or a document; quotes stay exactly as written.

This is a saved copy of the skill's SKILL.md instructions. It may differ from the upstream file or the version you install.

In this document (6)

Writing simplified technical English

ASD-STE100 is a controlled-language standard. The aerospace and defense industry wrote it so that a technician cannot misread a maintenance instruction. It removes the two biggest sources of misreading: words that carry more than one meaning, and sentences that support more than one structure.

The same discipline fixes the usual failure of agent-written prose. Agent output is often correct and unreadable: long sentences, stacked hedges, passive voice, and a synonym rotation that makes one action look like three. The reader has no author to ask, so ambiguity costs them a re-read at best and a wrong action at worst.

Apply the rules below as you write. Do not write a dense draft and clean it up afterward.

When to use this

Use it for text that a person or another agent must act on:

Reports, findings, and summaries.
PR descriptions, commit messages, and code comments.
Instructions passed to another agent, and prompts.
Tool descriptions, error messages, empty states, and log lines.

Do not use it where voice is the point: marketing copy, blog posts, or anything persuasive. STE is deliberately flat. Also leave quoted text alone. If you quote a user, a log, or a document, quote it as it is.

The rules

Rule	Do	Do not
One meaning per word	Pick one verb per action and reuse it every time	Rotate "check", "verify", and "confirm" for the same action
One part of speech per word	"Apply oil to the valve"	"Oil the valve"
Active voice	"The worker deletes the file."	"The file is deleted."
Simple tenses	"We received the report."	"We have received the report."
One idea per sentence	"Open the file. Read line 3."	"Open the file and read line 3, then check it matches."
Sentence length	20 words or fewer for instructions, 25 or fewer for descriptions	Chains of subordinate clauses
Noun clusters	3 words or fewer ("fuel pump valve")	"high pressure fuel pump inlet valve assembly"
No missing words	Keep the subject, the verb, and the article, even if it reads longer	"Files not backed up will be lost", which hides which files
One hedge, at most	"The client version is probably out of date."	"An error may have occurred which could be caused by..."
Paragraphs	One topic, 6 sentences or fewer	Multi-topic paragraphs
Lists	Use a list for 3 or more steps or conditions	A sequence buried in one sentence
Jargon	Keep the technical term you need, and define it once	Use an internal name the reader has never seen

PostHog house style sits on top of these rules and wins where the two disagree. We use American English, sentence case, and the Oxford comma. We do not use the em-dash.

How to rewrite

Read the text once for meaning. Do not start rewriting before you know what it must still say.
Go sentence by sentence. Name the rule each sentence breaks.
Rewrite the sentence to fix that break. Keep every fact, number, condition, and qualifier.
Check the result against the rules again. A rewrite often introduces a new long sentence.

Precision beats brevity. If a shorter sentence would drop a safety condition, a scope qualifier, or a number, keep the longer sentence and say why.

If the text already follows the rules, say so. Do not change compliant text.

Self-check

Before you send the text, read it once and ask:

Does any sentence run past 25 words?
Does any sentence carry two instructions?
Does the same action appear under two different verbs?
Can a passive sentence name its actor?
Would a reader who joins here, with no context, know what to do next?

References

references/writing-rules.md: the detail behind the table, plus sources.
references/before-after.md: worked examples of the rewrite, including agent output.

This skill ships inside the PostHog AI Plugin. Listed package contents include 3 slash commands, 1 agent, hooks and an MCP server. Installed components and skill versions may vary by AI tool.

Install just this skill

Run this outside your AI tool, using Node.js 22.20.0 or newer. Skills CLI 1.7.2 skips skill selection; prompts cancel installation without an interactive terminal. If choosing Project when asked about installation scope, open your project's folder before running this.

Install checklist

Check selected tools if a picker appears; Claude Code may be unchecked under Additional agents. ↑/↓ moves, Space toggles selections, Enter confirms.
Without a tool picker, check Installing to: for your intended tool. Stop if it names a different tool.
If asked, choose Symlink (Recommended) for shared files or Copy to all agents for separate copies; review the summary before confirming installation.
Install the find-skills skill? defaults to Yes, adding another skill for all projects. Choose No if you don't want that extra installation.

Skills CLI 1.7.2 sends install data to skills.sh by default, including the source, skill names, target tools and file details; GitHub sources are reported only when GitHub confirms the repository is public, while other remote sources can also be reported. Confirmed-public GitHub sources also trigger a security-audit request. Before installing, set the environment variable DO_NOT_TRACK=1 or DISABLE_TELEMETRY=1 to disable both.

npx skills add posthog/ai-plugin --skill "writing-simplified-technical-english" --full-depth

After installing for Claude Code, open it in the installation project if you chose Project; Global makes the skill available across projects on this computer. Once Claude Code loads the skill, its description helps Claude decide when to use it.

If installation created a top-level skills folder that did not exist when your Claude Code session started, run /reload-skills in that session. Run it again after later changes in that folder.

Install the whole plugin

This route installs the posthog plugin package selected for your AI tool.

Claude Code

Add PostHog's marketplace, then install the plugin

Run both lines in a terminal. They install PostHog's posthog plugin: this skill, PostHog's other skills, and a connection to PostHog's hosted MCP server.

claude plugin marketplace add PostHog/ai-plugin

02
```
claude plugin install posthog@posthog
```

Installation and loading

The plugin installs for you in every project and loads the next time you start Claude Code, or after /reload-plugins in an open session.
To connect your PostHog account, start claude, type /mcp, select plugin:posthog:posthog and follow the browser prompts.

Good to know

The plugin includes PostHog's session-capture hook; PostHog's README says it sends sessions to LLM Analytics only when POSTHOG_LLMA_CC_ENABLED=true and POSTHOG_API_KEY are both set.
If you use the separate posthog-telemetry plugin, PostHog says to keep only one of the two, because both register the same hook.
On a self-hosted PostHog, this route's MCP connection won't reach your instance: the plugin's config is fixed to https://mcp.posthog.com/mcp, which routes to PostHog's US or EU region. POSTHOG_MCP_URL works only for the Gemini CLI extension.

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Writing simplified technical English

When to use this

The rules

How to rewrite

Self-check

References

No requirements beyond installing this skill were found.

Install just this skill

Install the whole plugin

Add PostHog's marketplace, then install the plugin

More skills

adding-warehouse-person-properties

analyzing-expensive-users

analyzing-experiment-session-replays

assessing-heatmaps

auditing-endpoints

auditing-experiments-flags