feat(skills-catalog): add optional /simplified-english skill (#10410)

## Thinking Path

> - Paperclip is the open source app people use to manage AI agents for
work
> - Agents draw writing behavior from installable skills in the shipped
skills catalog (`packages/skills-catalog`)
> - Agent-authored comments, plans, and documents are often wordy or
ambiguous, which slows human readers
> - A small, opt-in skill can set a clear house style for user-facing
prose without touching agent code
> - This pull request adds an optional `simplified-english` catalog
skill that tells agents to write user-facing comments, plans, and
documents in ASD-STE100 Simplified Technical English
> - The benefit is shorter, unambiguous, one-meaning-per-sentence
writing that readers understand on the first pass

## Linked Issues or Issue Description

<!-- Feature request (no public GitHub issue). Described inline per
CONTRIBUTING.md → "Link Issues or Describe Them In-PR". -->

**Problem or motivation**

Agent-authored user-facing text (issue comments, plans, documents) is
frequently long-winded, uses inconsistent vocabulary, and packs multiple
instructions into one sentence. Readers have to re-read it. There is no
shared, installable house style for clear technical writing.

**Proposed solution**

Add an optional content skill, `simplified-english`, to the shipped
catalog. It instructs agents to write user-facing comments, plans, and
documents using only ASD-STE100 Simplified Technical English (short
sentences, one instruction each, approved single-meaning words, active
voice, present tense). Orgs opt in by installing it.

**Alternatives considered**

Baking the guidance into every agent's base instructions (too broad, not
opt-in) or a bundled skill (would apply everywhere by default). An
optional skill keeps it opt-in per org.

**Roadmap alignment**

Additive, opt-in catalog content only; no core behavior change.

## What Changed

- Add
`packages/skills-catalog/catalog/optional/content/simplified-english/SKILL.md`
— a short optional skill instructing agents to write user-facing
comments, plans, and documents in ASD-STE100 Simplified Technical
English. Includes an "Approved words" section that identifies the
controlled vocabulary (the ASD-STE100 Dictionary) and gives concrete
house-choice substitutions.
- Regenerate `packages/skills-catalog/generated/catalog.json` via
`build:manifest` so the manifest includes the new skill.
- Pin the new catalog key in
`packages/skills-catalog/src/shipped-catalog.test.ts`.

## Verification

- `pnpm --filter @paperclipai/skills-catalog build:manifest` → wrote
manifest with the new skill.
- `pnpm --filter @paperclipai/skills-catalog validate` → "Catalog
manifest is valid".
- `pnpm --filter @paperclipai/skills-catalog test` → the catalog
set/count/key pinning tests pass with the new skill included.
- Confirmed the generated entry: key
`paperclipai/optional/content/simplified-english`, trustLevel
`markdown_only`, description within the 300-char budget cap.

## Risks

Low risk. Additive, markdown-only optional skill plus a regenerated
manifest and a pinning-test update. No runtime code, migrations, or
workflow changes. Not installed by default (`defaultInstall: false`).

## Model Used

Claude Opus 4.8 (1M context), extended thinking, with tool use / code
execution.

## Checklist

- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used (with version and capability
details)
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work
- [x] I have searched GitHub for duplicate or related PRs and linked
them above
- [x] I have either (a) linked existing issues with `Fixes: #` / `Closes
#` / `Refs #` OR (b) described the issue in-PR following the relevant
issue template
- [x] I have not referenced internal/instance-local Paperclip issues or
links
- [x] My branch name describes the change and contains no internal
Paperclip ticket id
- [x] I have run tests locally and they pass
- [x] I have added or updated tests where applicable
- [x] I have updated relevant documentation to reflect my changes
- [x] I have considered and documented any risks above
- [ ] All Paperclip CI gates are green
- [ ] Greptile is 5/5 with no open P2s, recommendations, or follow-ups
- [x] I will address all Greptile and reviewer comments before
requesting merge

---------

Co-authored-by: Paperclip <noreply@paperclip.ing>

packages/skills-catalog/catalog/optional/content/simplified-english/SKILL.md

@@ -0,0 +1,40 @@
+---
+name: simplified-english
+description: Write user-facing comments, plans, and documents in ASD-STE100 Simplified Technical English — short, unambiguous sentences with approved words and one meaning each — so readers understand them the first time.
+key: paperclipai/optional/content/simplified-english
+recommendedForRoles:
+  - engineer
+  - product
+  - writer
+  - devrel
+tags:
+  - writing
+  - communication
+  - clarity
+  - style
+---
+
+# Simplified English
+
+For user-facing comments, plans, and documents, write using only ASD-STE100 Simplified Technical English.
+
+## Core rules
+
+- Use short sentences (procedures ≤ 20 words, descriptions ≤ 25 words).
+- Give one instruction per sentence.
+- Use approved words with one meaning each; avoid synonyms and jargon.
+- Use the active voice and the present tense.
+- Use articles ("the", "a") and do not drop words to save space.
+- Write positive instructions; avoid negative or vague qualifiers.
+- Keep paragraphs to one topic.
+
+## Approved words
+
+The approved words are the ASD-STE100 controlled vocabulary — the Dictionary in the current ASD-STE100 specification, plus the technical names and technical verbs that your subject needs. When a word is not approved, use the simplest common word that has one meaning. Prefer these house choices:
+
+- "start" / "stop" (not "initiate", "commence", "terminate", "kill")
+- "make" (not "implement", "leverage", "utilize")
+- "before" / "after" (not "prior to", "subsequent to")
+- "about" (not "regarding", "in relation to")
+- "help" (not "facilitate")
+- "use" (not "utilize", "employ")

packages/skills-catalog/generated/catalog.json

@@ -2,7 +2,7 @@
   "schemaVersion": 1,
   "packageName": "@paperclipai/skills-catalog",
   "packageVersion": "0.3.1",
-  "generatedAt": "2026-07-24T18:19:49.696Z",
+  "generatedAt": "2026-07-28T22:35:25.645Z",
   "skills": [
     {
       "id": "paperclipai:bundled:docs:doc-maintenance",
@@ -485,6 +485,42 @@
       ],
       "contentHash": "sha256:efe8ea89b552df95222609867c9c75f1b40e16f457d34e7e4a124f54daa33efa"
     },
+    {
+      "id": "paperclipai:optional:content:simplified-english",
+      "key": "paperclipai/optional/content/simplified-english",
+      "kind": "optional",
+      "category": "content",
+      "slug": "simplified-english",
+      "name": "simplified-english",
+      "description": "Write user-facing comments, plans, and documents in ASD-STE100 Simplified Technical English — short, unambiguous sentences with approved words and one meaning each — so readers understand them the first time.",
+      "path": "catalog/optional/content/simplified-english",
+      "entrypoint": "SKILL.md",
+      "trustLevel": "markdown_only",
+      "compatibility": "compatible",
+      "defaultInstall": false,
+      "recommendedForRoles": [
+        "engineer",
+        "product",
+        "writer",
+        "devrel"
+      ],
+      "requires": [],
+      "tags": [
+        "writing",
+        "communication",
+        "clarity",
+        "style"
+      ],
+      "files": [
+        {
+          "path": "SKILL.md",
+          "kind": "skill",
+          "sizeBytes": 1578,
+          "sha256": "a0f7385599873910e2fabf400346016a07dacbc7ece27c0e3616ae8fd94ebfbb"
+        }
+      ],
+      "contentHash": "sha256:642321f40d51e0125df05c6fbace49aeb07ec30392058756909c259c9c5eac6a"
+    },
     {
       "id": "paperclipai:optional:finance:ramp",
       "key": "paperclipai/optional/finance/ramp",

packages/skills-catalog/src/shipped-catalog.test.ts

@@ -20,6 +20,7 @@ const EXPECTED_BUNDLED_KEYS = [
 const EXPECTED_OPTIONAL_KEYS = [
   "paperclipai/optional/browser/agent-browser",
   "paperclipai/optional/content/release-announcement",
+  "paperclipai/optional/content/simplified-english",
   "paperclipai/optional/finance/ramp",
   "paperclipai/optional/product/design-critique",
   "paperclipai/optional/research/last30days",