Workflows

Spec-Driven Development with AI Agents

The biggest quality lever when working with AI agents is not a better prompt. It is a clear spec. When you capture intent before the agent writes a line, you turn a guesser into a reliable executor.

Why intent capture beats prompting

An agent fills every gap in your request with an assumption. Vague in, plausible-but-wrong out. A spec removes the guesswork: it states the goal, the constraints, and what done looks like, so the agent is executing a decision you already made instead of inventing one for you.

What a working spec contains

A spec does not need to be long. It needs to be unambiguous. The minimum that earns its keep:

  • The goal: what changes for the user or the system, and why.
  • Constraints: the interfaces, patterns, and boundaries the agent must respect.
  • Acceptance criteria: the observable conditions that make this correct.
  • Out of scope: what the agent should explicitly not touch.

The loop: spec, execute, review, refine

Spec-driven work runs as a tight feedback loop, not a one-shot. You write the spec, the agent executes, you review against the acceptance criteria, and you refine the spec where reality disagreed with your plan. Each turn the spec gets sharper and the output gets closer, which is exactly the opposite of the prompt-and-pray spiral.

Specs as the unit of review

The cheapest place to catch a mistake is in the intent, not the output. Reviewing the spec before the agent runs costs minutes; reviewing thousands of generated lines after the fact costs hours and misses things. Make the spec the artifact the team reviews, and the code review becomes a verification step rather than an archaeology dig.

Multi-agent work needs specs even more

The moment you run agents in parallel, a shared written contract stops being optional. Without it, two agents make incompatible assumptions and you spend the saved time reconciling them. The spec is what lets parallel work converge instead of diverge.

Frequently asked questions

Isn't writing specs slower than just prompting? βŒ„

You pay a few minutes upfront and save hours of rework. For anything beyond a trivial change, spec-first is the faster path to shipped, correct code.

How detailed should a spec be? βŒ„

Detailed enough that a competent stranger, or an agent, could execute it without asking you what you meant. No more than that.

Where should specs live? βŒ„

In the repository, versioned, next to the code they describe. They are part of the engineering record, not a throwaway prompt.

Make spec-driven the default on your team

Spec-driven development is the habit that most reliably moves a team from erratic AI output to predictable delivery. If you want to build that muscle across your engineering org, a workshop or advisory engagement is the fastest way in.