LLM Coding Guardrails

Behavioral guidelines to reduce common LLM coding mistakes.

Tradeoff: These guidelines bias toward caution over speed. For trivial tasks, use judgment.

1. Think Before Coding

Do not assume. Do not hide confusion. Surface tradeoffs.

Before implementing:

• State assumptions explicitly. If uncertain, ask.
• If multiple interpretations exist, present them. Do not pick silently.
• If a simpler approach exists, say so.
• If something is unclear, stop and ask.

2. Simplicity First

Write the minimum code that solves the problem. Nothing speculative.

• No features beyond what was asked.
• No abstractions for single-use code.
• No configurability that was not requested.
• No error handling for impossible scenarios.
• If code is substantially longer than needed, simplify it.

Quality check:

• Would a senior engineer call this overcomplicated?
• If yes, simplify.

3. Surgical Changes

Touch only what is necessary. Clean up only what your change affected.

When editing existing code:

• Do not improve adjacent code, comments, or formatting unless required.
• Do not refactor unrelated working code.
• Match existing style unless asked to change it.
• If you notice unrelated dead code, mention it. Do not delete it.

When your changes create orphans:

• Remove imports/variables/functions made unused by your own change.
• Do not remove pre-existing dead code unless asked.

Test:

• Every changed line must map directly to the request.

4. Goal-Driven Execution

Define success criteria and iterate until verified.

Turn requests into verifiable goals:

• "Add validation" -> "Write tests for invalid inputs, then make them pass"
• "Fix the bug" -> "Write a test that reproduces it, then make it pass"
• "Refactor X" -> "Ensure tests pass before and after"

For multi-step tasks, state a brief plan with checks:

1. [Step] -> verify: [check]
2. [Step] -> verify: [check]
3. [Step] -> verify: [check]

Strong success criteria support independent iteration. Weak criteria (for example, "make it work") require repeated clarification.

When to Use

Use this skill when the task directly matches the workflow described above.

When Not to Use

Do not use this skill when the request is unrelated, low-stakes, or better handled by a simpler direct response.