A mid-market brand used an agent to generate 500 product descriptions, finishing the first draft in under an hour.
A junior marketing manager was asked to review the copy. By the third description, problems were obvious.
‘Delve into a world of comfort.’
‘Unleash the power of sustainable living.’
What should have been a quick check became a week of manual editing. The manager fixed the same errors on a loop: stripping clichés, tightening tone, and adding back mandatory details.
The agent hadn’t saved work; it had just shifted it to expensive human oversight.
The Prompt Mirage
The team believed a prompt could guarantee on-brand content. Managers saw coherent text and assumed the job was done. It failed for two reasons.
Brand knowledge is implicit. The real voice of a brand lives in people’s heads. It is shaped by unwritten rules, past decisions, and judgement built over time. None of this exists in a prompt unless made explicit.
Scale makes this worse. The same mistake across 500 descriptions becomes an editing tax. Humans stop editing and start policing output.
The Fix: Treat Brand Voice as a System
A Brand Constitution is a set of machine-readable rules that define how the brand speaks. A second agent enforces them.
1. Brand Constitution Schema
Category
Rule
CORE PRINCIPLE
Helpful expert, not a pushy salesperson. Confident, clear, respects the reader’s intelligence.
AUDIENCE ASSUMPTION
Assume the reader is smart, busy, and has done basic research. Get to the point.
FORBIDDEN PHRASES
‘delve into’, ‘unleash the power’, ‘game-changer’, ‘in today’s fast-paced world’
MANDATORY ELEMENTS
Product descriptions must state material and country_of_origin.
SENTENCE STRUCTURE
Average sentence length under 15 words. No more than two consecutive sentences start with the same word.
TONE GUARDRAIL
Avoid hedging language (might, could). Use active voice.
2. The Critic’s Scorecard
Violation
Severity
Result
Feedback
Forbidden phrase
HIGH
FAIL
‘The draft used “delve into” in paragraph 2. Rewrite to be more direct.’
Missing element
HIGH
FAIL
‘The description is missing country_of_origin. Add this information.’
Structure issue
LOW
PASS
‘Three sentences exceed 15 words. Consider breaking them up.’
No violations
N/A
PASS
‘Draft approved. Ready for human review.’
Operational Setup
1. Codify the Brand Voice
Gather your top 20 best-performing emails, product pages, or articles. Feed them into a model and extract the rules that already exist but are undocumented.
Prompt: “I am pasting 20 examples of our best writing. Analyse the tone, sentence structure, and vocabulary. Output a structured ‘Brand Constitution’ with the following fields:
Five adjectives that describe our voice
Five forbidden phrases we never use
Our rules for sentence length and structure.”
Refine the output with your CMO or Brand Lead. Instinct becomes syntax.
2. Build the Critic Agent
Its role is narrow. Do not let it write.
System Prompt:
Role: You are the Brand Critic. You do not write. You only grade.
Input: A draft product description.
Context: [PASTE BRAND CONSTITUTION HERE]
Task: Check the draft against the Constitution.
Output: Provide a structured response with the following fields: status (either “PASS” or “FAIL”), violations (a list of specific rules broken), and feedback (instructions for the writer).
3. Connect the Loop
Use an orchestration tool (like Make or Zapier) to wire the agents together.
The writer agent produces a draft.
The critic checks it.
If PASS: It moves to human review.
If FAIL: The structured feedback is sent back to the writer agent.
The writer produces a revised version immediately.
The critic checks it again.
Only drafts that fail twice are escalated.
4. Review Exceptions, Not Drafts
At that point, editors stop reviewing drafts. They review decisions. On a weekly cadence, they scan critic failures and spot-check passes. When patterns emerge, they update the Constitution. Humans stop fixing copy. They maintain the system that governs it.
Executive Takeaway
By separating creation from critique and by building a self-healing loop, agents don’t just generate volume. Value comes from the loop itself. Humans stop fixing repetitive errors and start improving the rules of the game. Speed increases while the brand stays protected.