Use when writing, reviewing, shortening, tightening, deduplicating, or compressing any skill file, system prompt, subagent prompt, or CLAUDE.md — including when asked to "fix" or "improve" a prompt file.
Every token costs context window in every session. Waste is cumulative.
Core rule: Every word earns its place. Removing a word doesn't change behavior? Remove it.
| # | Rule | Example |
|---|---|---|
| 1 | One idea per sentence | Split compounds. Cut conjunctions. |
| 2 | Rule first, not reasoning | "Never push without approval" not "Because pushing can cause..." |
| 3 | Tables over prose | Rows scan; paragraphs don't. |
| 4 | No filler | Cut: "It is important to", "Make sure to", "In order to" |
| 5 | Define once, reference elsewhere | Rule in table AND prose AND red flags? Keep table. |
| 6 | Imperatives | "Tag all claims" not "All teammates should tag their claims" |
| 7 | Specific over abstract | "Reject bare uint64" not "Ensure strong typing" |
| 8 | Examples compress | One precise example replaces a paragraph. |
| Verbose | Concise |
|---|---|
| "must make sure to always verify that..." | "verifies..." |
| "It is important to note that this is non-negotiable" | (delete) |
| "In the event that a teammate fails to respond" | "Teammate unresponsive:" |
| "Each and every factual claim must be tagged" | "Tag all claims" |
| "Before marking any task as complete, they must verify against..." | "Before marking done:" |
description)Always-loaded. Optimize for match, not compression.
| Rule | Example |
|---|---|
| First 6 words carry the trigger | Use when writing or shortening... not This skill helps when... |
| List verbs users actually say | writing, reviewing, shortening, fixing — cover synonyms |
| Enumerate file types + aliases | skill file, SKILL.md, system prompt, CLAUDE.md |
| Name the failure the skill prevents | ...ensures every word earns its place |
Bad → good:
description: helps with prompts → description: Use when writing, reviewing, or shortening skill files, system prompts, CLAUDE.mddescription: for skill authoring → description: Use when writing or editing any SKILL.md, agent prompt, or CLAUDE.md — including "fix this prompt" and "tighten this"No fixed word budget. The target is marginal value per word: every rule, every example, every sentence must change reader behavior. A 3000-word skill that eliminates repeated failures earns its length; a 200-word skill with filler does not.
Test: 20%+ word reduction with same rules = better version.
| Symptom | Fix |
|---|---|
| Same rule in 3+ places | Keep one |
| "It is" / "There are" opener | Imperative |
| Prose restating a table | Delete prose |
| "Must should always" stacking | One verb |
| +10% words, no new rules | Revert |