I can identify AI writing in two seconds. Not because it's wrong or incoherent — it's usually quite competent. It's because it sounds like everyone and no one simultaneously. Generic sentence rhythm. Safe word choices. A faint smell of corporate communication. The cause isn't the model's capability — it's the absence of signal about voice, opinion, and constraint. Structured writing prompts eliminate all three deficits.
This example targets a newsletter article — one of the most voice-sensitive writing types. Notice how the PERSONA band encodes a distinct worldview, not just a job title:
{
"formula": "x(t) = Σ x(nT) · sinc((t - nT) / T)",
"T": "specification-axis",
"fragments": [
{
"n": 0,
"t": "PERSONA",
"x": "You are a former YC founder who sold a company and now writes about the reality of building startups. Your voice is direct, occasionally sardonic, and grounded in specifics rather than platitudes. You use short sentences. You state opinions as facts. You never say 'it depends' without immediately saying what it depends on."
},
{
"n": 1,
"t": "CONTEXT",
"x": "This is a weekly newsletter to 8,500 subscribers who are early-stage founders. Most are at the pre-seed to Series A stage. The newsletter has a reputation for being unusually honest — readers unsubscribe when it goes soft."
},
{
"n": 2,
"t": "DATA",
"x": "Topic: Why most founders should not hire a Head of Sales in year one. Key insight: founders who hand off sales before product-market fit almost always regret it. Supporting points: (1) sales feedback loop breaks, (2) hired salesperson can't sell what the market hasn't validated yet, (3) you stop talking to customers."
},
{
"n": 3,
"t": "CONSTRAINTS",
"x": "No listicles. No bullet points. Prose only. No hedging phrases like 'it might be worth considering.' No 'In conclusion.' No starting a sentence with 'However.' Each paragraph must advance the argument — no decorative transitions. Do not use the word 'journey.' Do not use exclamation marks."
},
{
"n": 4,
"t": "FORMAT",
"x": "Opening hook (1 paragraph, under 60 words). Body (3-4 paragraphs, 100-150 words each). Closing punch (1 paragraph, under 40 words). Total: 500-700 words. No headers."
},
{
"n": 5,
"t": "TASK",
"x": "Write the newsletter article arguing founders should not hire a Head of Sales in year one."
}
]
}Voice in writing comes from three things: sentence rhythm, word choice, and opinionation. Generic AI writing fails on all three because without explicit guidance, the model defaults to its statistical average — which is moderately formal, moderately hedged, and rhythmically predictable.
The PERSONA band in a writing prompt does something different from a coding prompt: it encodes beliefs and behavioral constraints. "States opinions as facts" changes the model's assertion confidence. "Never says 'it depends' without immediately specifying what it depends on" eliminates the hedge-and-punt failure mode. "Short sentences" shifts the rhythm at the token level.
Writing prompt tip: The CONSTRAINTS band is where you ban the AI writing fingerprints. Every "however," every "in conclusion," every "it's worth noting" is a tell. List 5-8 specific phrases or patterns you want eliminated. The model will actively suppress them rather than accidentally including them.
Write a newsletter article about why founders shouldn't hire a Head of Sales too early. Write for startup founders. 600 words, conversational tone.
PERSONA: Former YC founder, sardonic, states opinions as facts, no 'it depends.'
CONSTRAINTS: No listicles. No hedging. No 'However.' No 'journey.' No '!'
FORMAT: Hook + 3-4 body paragraphs + closing punch. 500-700 words. No headers.
The raw prompt produces a competent but anonymous article. The structured prompt produces writing with a specific voice that readers recognize issue-to-issue. The difference is the signal you put in.
Try AI Transform — Structure Your Writing Prompt Free