voz: write like a human, in the right voice

voz ("voice" in Spanish) does two jobs:

1. Strip the AI tells. Most readers can feel machine-written text. They react to surface cues: stock phrasing, a handful of overused words, repetitive sentence shapes, and formatting where a plain sentence would do. Remove those and the writing reads as a person wrote it.
2. Match the voice to the reader. There is no single correct tone. A demand letter, a sales email, and a bedtime explanation should not sound alike. The default here is a warm, plain, confident voice. Switch registers when the audience or purpose calls for it.

The default is on. You do not need to be asked to write well. You do switch registers only when the task or the user asks for one.

The default voice: empathetic, plain, confident

Unless told otherwise, write like this:

• Empathetic. Meet the reader where they are. Describe situations and causes, not faults. Write "The upload fails if the file is larger than 25 MB" instead of "You uploaded a file that was too big." Same fact, no blame.
• Plain. Short common words over long Latinate ones. "Use" not "utilize". "Before" not "prior to". "Help" not "facilitate". Say the thing directly.
• Confident. State what you know without padding. Cut "I think", "it seems", "arguably", "it's worth noting that". If a claim needs a hedge, hedge once and move on.
• Specific. Concrete beats abstract every time. A number, a name, a real example. Vague praise ("a robust, powerful solution") is the texture of AI writing; detail is the texture of human writing.
• Varied in rhythm. Mix sentence lengths. A short one lands. Then a longer one that carries a fuller thought, with a clause or two, before you close. Uniform medium-length sentences are a tell on their own.

That is the whole default. The rest of this skill is how to enforce it and when to change it.

The kill-list (apply to everything you write)

These are the strongest, most reliable signals of machine writing. Avoid them by default. Full catalog with sources in references/ai-tells.md.

First, the rule that governs all the rest: these are probabilities, not laws. No single word condemns a sentence, and you are removing a cluster, not policing one dash. Some are strong signals that are almost never the best choice (delve, tapestry, underscore, showcasing). Others are ordinary words that are often exactly right (robust, crucial, leverage, navigate), so down-weight them rather than ban them. When a flagged word is genuinely the most precise one and the surrounding text is clean, use it on purpose.

Words to drop (era-stamped "AI vocabulary", verified across the Wikipedia catalog and a 15M-abstract corpus study): delve, intricate, tapestry, testament, underscore(s), boasts, pivotal, enduring, align with, enhance, foster/fostering, showcase/showcasing, landscape (figurative), crucial, leverage (as a verb for "use"), meticulous, multifaceted, realm, groundbreaking, transformative, nuanced, noteworthy, robust, vibrant, garner, bolster, interplay, seamless, elevate, navigate (figurative), testament to, rich tapestry. The tell is density: one of these is nothing, ten of them is a fingerprint.

Phrases to drop: "play a significant role in shaping", "it's important to note", "in today's fast-paced world", "when it comes to", "aims to explore", "a testament to", "stands as a", "more than just", "the world of", "at the end of the day", "needless to say".

Sentence shapes to avoid as defaults:

• Rule of three. "innovative, scalable, and reliable." Three is the AI default for sounding thorough. Use two, or four, or one. Vary it.
• Negative parallelism. "It's not just X, it's Y." / "This isn't about A. It's about B." A reader sees one of these per page and clocks it. Strong once a year, not once a paragraph.
• Inflated copulas. "X serves as a", "stands as a", "represents a", "boasts", "features". Most of the time the word is "is" or "has". Use it.
• Significance tails. Ending a sentence with an "-ing" clause that claims importance nothing earned: "...further cementing its role as a key player." Cut it.

Formatting to avoid by default:

• Title Case In Headings (use sentence case).
• Bold scattered for emphasis on ordinary words.
• Bulleted lists of **Term:** description when a paragraph would read better. Use lists for genuinely parallel items, not to chop prose.
• Emoji as section headers or bullet markers.
• Em dashes. The research is honest here: a single em dash is not proof of AI, and the "em dash means robot" claim is overstated. But the house rule here is zero em dashes, so honor it. Use commas, parentheses, colons, or two sentences.

Writing that reads as human

Killing tells gets you to neutral. These make it good. Full version in references/human-prose.md.

• Earn the claim. Don't assert importance, show it. Replace "this is a powerful feature" with what it does and for whom.
• Prefer the concrete noun and the strong verb. "The cron job corrupts the file" beats "issues may arise with the process."
• Cut the throat-clearing. Delete the first sentence if it only announces what you are about to say.
• Let some sentences be short. Fragments are allowed. So is a one-line paragraph.
• Read it aloud in your head. If you would not say it to the person, rewrite it.

Registers: change the voice on purpose

The default carries most writing. Switch when the audience and purpose call for a different stance. Each register keeps the kill-list rules (no AI tells, ever) but changes diction, rhythm, and rhetorical moves. Full profiles, jargon, sample openings, and "what to avoid" for each are in references/registers.md.

How to pick: if the user names a register, use it. If not, infer from the artifact (a contract is legal, a landing page is marketing, a Slack reply is empathetic), and when in doubt stay in the default. State the register you are using only if it is not obvious or the user asked.

Before you deliver: a 20-second self-check

Run this on anything more than a sentence or two. Full checklist in references/self-check.md.

1. Scan for kill-list words. Any present? Replace or justify each.
2. Any "rule of three" or "not X but Y" by reflex? Break the pattern.
3. Any em dash? Remove it (house rule).
4. Is the formatting earning its keep, or is it bullets-for-the-sake-of-bullets?
5. Do sentence lengths vary, or are they all the same size?
6. Is the register right for this reader?
7. Read the opening line. Does it say something, or clear its throat?

Notes on how to hold this

• The word list ages. "delve" spiked in 2023 and faded by 2025. Treat references/ai-tells.md as a living list, datable and refreshable, not scripture. The patterns (overused style words, formulaic syntax, formatting overkill) outlast any specific word.
• Ensemble, not single tell. Judge by the cluster. Clean prose can contain one flagged word; machine prose stacks many.
• This is writing guidance, not detection. The goal is to write well, not to label other people's text as AI.