Agent Skill
Constraint Driven Development skill
constraint-driven-developmentaddyosmani/agent-skillsskills/constraint-driven-development/SKILL.md
Establishes a project's quality bar as a written contract and stops agents quietly lowering it. Interviews the user on which dimensions matter, supplies sane default thresholds when they have no number in mind, records everything in CONSTRAINTS.md, and watches the diff for a weakened bar — new @ts-ignore or eslint-disable suppressions, skipped or deleted tests, assertions stripped out, unimplemented stubs, thresholds edited down. Use when no quality bar is written down, when the user says "set up constraints" or "define our standards", when the user wants dimensions they care about — accessibility, web performance, coverage — set up as enforced constraints, when an agent keeps silencing checks or skipping tests to get to green, when you need a coverage or performance threshold and don't know what number to pick, or when an agent writes more code than anyone will read.
always on
175 tokname + description
once used
4,788 tokSKILL.md body
bundled files
110 KB
repo stars
109kGitHub
Install the Constraint Driven Development skill
Skills CLI (Claude Code, Codex, Cursor and others)
npx skills add https://github.com/addyosmani/agent-skills --skill constraint-driven-development
Claude Code, by hand (all projects)
git clone --depth 1 https://github.com/addyosmani/agent-skills.git /tmp/agent-skills mkdir -p ~/.claude/skills cp -R /tmp/agent-skills/skills/constraint-driven-development ~/.claude/skills/constraint-driven-development
For one project only, copy the folder into .claude/skills/ in that project instead. The agent picks it up when a task matches its description.
What it costs your context
Agent Skills load in three steps. Tokens counted with the o200k tokenizer; your model's count will differ a little.
| When | What loads | Cost |
|---|---|---|
| Every session | Name and description | 175 tok |
| When the agent uses it | The SKILL.md instructions | 4,788 tok |
| Only if opened | 1 bundled files (10 KB) | varies |
Until it is used, constraint-driven-development costs about 7.8× less than the median MCP server we measured (1,362 tokens on every turn). Installing all 25 skills from addyosmani/agent-skills would load 1,829 tokens of descriptions. Skills vs MCP study
Checks
Our checks found nothing to flag: it follows the Agent Skills specification's naming and size guidelines and doesn't pipe downloads into a shell.
Checked 2026-10-22 · method
What's inside
The headings of its SKILL.md. Read the full file on GitHub.
- Constraint-Driven Development
- Overview
- When to Use
- Loading Constraints
- The Process
- Step 1: Detect before you ask
- Step 2: Four questions, each with a default
- Step 3: Write CONSTRAINTS.md
- Step 4: Install what each dimension needs
- Step 5: Wire it to the lifecycle
- Step 6: Guard the bar itself
- Step 7: Ratchets, when you don't have a number
- Sane Defaults
- Escalation Path
- Common Rationalizations
- Red Flags
- Verification
- See Also
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