Product ManagementAI AgentsEngineering

Writing PRDs for AI Agents: The New Engineering Standard

Sarah Chen, Principal PM
April 2, 2025
10 min read

"The greatest friction in AI development is the gap between what you said and what the agent thought you meant."

In the past, a PRD was a document designed to start a conversation. In 2025, a PRD is a System Specification designed to guide an autonomous worker. If your PRD contains words like "clean", "fast", or "intuitive" without metrics, your AI agent will hallucinate its own definitions.

Deterministic Specs vs. Human PRDs

An "Agent-Ready" PRD must transition from descriptive prose to prescriptive logic. It needs to define state transitions, API contracts, and architectural boundaries before the first line of code is written.

ComponentHuman PRD (Vague)Agent Spec (Deterministic)
Auth"Make it secure.""Inject @corp/auth-v2. Use RLS Policy: UID matches user_id."
Error Handling"Show an error message.""Catch 429: Toast 'Rate limited'. Catch 403: Redirect /login."
Performance"Must be fast.""Max Bundle: 120kb. P95 API Latency < 200ms."

The Anatomy of an Agent-Ready PRD

1. Module Mapping

Explicitly state which existing internal packages must be used. Do not let the agent choose a public library if an internal one exists.

2. State Machine Definitions

Define all possible states of a feature. (e.g., 'Loading', 'Success', 'Empty', 'Error_Auth', 'Error_Network'). Agents excel at implementing states if they are enumerated.

How Prodmap Automates This

Prodmap’s Planning Agent scans your request and recursively asks: "What is the expected behavior for [Edge Case]?" until the spec is deterministic.

See the Spec Engine

Thanks for reading.