How to Set Coding Standards That AI Agents Follow

Configuration Files the Agent Reads

AI coding agents read the same configuration files that your linters and formatters use. ESLint configuration for JavaScript, Pylint or Ruff for Python, PHP_CodeSniffer for PHP, and similar tools all define rules that the agent follows. If your project has a .eslintrc, the agent writes code that passes ESLint. If your project has a pyproject.toml with formatting rules, the agent follows those rules.

Beyond linter configuration, agents read editor configuration files (.editorconfig), formatting tools (Prettier, Black, php-cs-fixer), and any custom configuration that defines how code should be structured. The more explicit your configuration, the more consistent the agent's output.

Project-Level Rules

Some coding standards are not captured in linter configurations. Architectural decisions, naming patterns for specific concepts, preferred approaches for common tasks, and team conventions that are too nuanced for automated tools all benefit from explicit documentation. A simple document that says "API responses always use this format" or "database access goes through the repository layer, never direct queries" gives the agent clear guidance.

The agent also learns standards from reading the existing code. If every existing API endpoint follows a specific pattern, the agent follows that pattern for new endpoints even without explicit documentation. But documenting conventions explicitly removes ambiguity and ensures consistency even when existing code has occasional deviations.

What Makes a Good Standard for AI

• Specific and verifiable: "Use descriptive variable names" is vague. "Variable names must describe their contents, minimum 3 characters, no abbreviations except id and url" is specific enough to follow consistently.
• Machine-readable when possible: Standards expressed as linter rules are enforced automatically. Standards expressed only in prose require the agent to interpret them, which introduces variation.
• Positive rather than negative: "Always use parameterized queries" is easier to follow than "do not use string concatenation in queries" because it tells the agent what to do rather than what to avoid.
• Consistent with existing code: Standards that match what the codebase already does are followed naturally. Standards that contradict existing code require the agent to decide which to follow, which adds complexity.

Enforcing Standards in the Review Step

The agent's self-review step is where standards are verified. After writing code, the review checks that every standard has been followed. If the review finds a violation, the agent fixes it before presenting the result. This means the human reviewer never sees standards violations, which makes code review faster and more focused on substance.

Evolving Standards Over Time

As your team's standards evolve, the agent adapts. Update your linter configuration, and the agent follows the new rules on the next task. Add a new convention to your documentation, and the agent applies it going forward. The agent does not carry baggage from old standards; it reads the current configuration each time.