Coding Principles

Coding Principles Skill

Purpose

Apply four operating principles to every code change: think before coding, simplicity first, surgical changes, goal-driven execution.

When to use

Use this skill as the default posture for any code edit. It constrains how changes are made; other skills decide what to build.

Inputs

• the change request
• the surrounding code and its conventions
• what "working" means for this change

Output

Return:

• a short statement of assumptions and the intended approach, before editing
• the minimal diff that satisfies the request
• the verification actually run, with its output
• anything deliberately left undone

Constraints

• Think before coding — state assumptions and the plan explicitly before the first edit; if two readings of the request produce different code, say which one you took
• Simplicity first — the minimum code that solves the problem; no speculative abstractions, config flags, or layers for requirements that do not exist yet
• Surgical changes — touch only what the task requires; no drive-by reformatting, renaming, dependency bumps, or reorganisation of unrelated files
• Goal-driven execution — define the success test upfront and loop until it passes; a change is not done because it looks right
• match the surrounding code's idiom, naming, and comment density rather than importing a personal style
• delete code rather than commenting it out
• when a principle conflicts with an explicit instruction, the instruction wins — note the tension once and proceed

Examples

• Fix a bug without refactoring the surrounding module
• Add a small feature and resist generalising it prematurely
• Review a diff for scope creep before committing