Pick the Smallest Container
Use the smallest thing that works: a CLAUDE.md line, then a skill, and a plugin only when you must bundle and share.
Where you'll practice this
One Promptles scenario teaches this principle directly.
Choose a Line, Skill, or Plugin
The repetition hunt turned up three candidates, written up in `candidates.md`, and Dana wants a plugin for each. A plugin is the heaviest home: its own folder, usually a manifest (the file that names and describes it) and a version number, a marketplace listing, and someone to…
Other principles in Constraints
Define Component Boundaries
When splitting a component, give the decisions already made and say nothing on screen should change.
Define Inputs and Outputs
Say what goes in, what comes out, and what happens with bad input. Leave the inside to Claude.
Define the Business Logic
Turn business words into exact rules: the fields, the thresholds, and how they combine.
Deprecate Before Removing
Keep the old name working for a release, point to the replacement, and announce when it goes away.
Describe Edge Cases
Name the unusual cases you know about and what should happen in each.
Describe Type Contracts
Tell Claude the rules the code doesn't show, like allowed values and optional fields. It can work out the rest.