Simplified Technical English (ASD-STE100)

ASD-STE100 is a controlled-language standard built by the aerospace and defense industry (ASD, the AeroSpace and Defense Industries Association of Europe) to stop maintenance technicians from misreading English instructions. The standard removes the two biggest sources of misreading: words with more than one meaning, and sentences with more than one possible structure.

This skill borrows that same discipline for a different reader: an AI agent or a downstream system that has to parse an English string — an error message, a tool description, an inter-agent instruction, a status report — without a human in the loop to resolve ambiguity. If a maintenance technician can misread "close the valve" as an adjective ("the valve that is near") instead of a command, so can a language model.

When to Use This Skill

• An agent's output (explanation, instruction, log message, tool description) reads as dense, jargon-heavy, or ambiguous.
• Text will be consumed by another agent, a translation pipeline, or a non-native English reader, and misparsing has a real cost.
• You are writing a prompt, system message, or tool description and want to remove ambiguity before a model ever sees it.
• You want a before/after comparison showing exactly which rule was violated and how the rewrite fixes it.

This skill is not for creative or marketing copy — STE is deliberately flat and literal. Do not apply it to text where voice, nuance, or persuasion is the point.

Source and Scope

This skill encodes the rule categories of ASD-STE100 Issue 9 (Jan 2025): 53 writing rules across 9 sections covering word choice, grammar, sentence structure, and style, backed by a dictionary of ~900 approved words (one meaning, one part of speech each) and ~1,200 words to avoid with suggested replacements. See references/writing-rules.md for the full rule summary and citations.