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Get Started Free →testdouble/agent-builder
Builds a new Claude Code agent (subagent) from scratch through a relentless, evidence-based interview that walks the agent's design tree decision-by-decision — entity fit, domain focus and vocabulary, role identity, anti-patterns, description, model tier, tools, and self-containment — then reviews the finished agent against the plugin-building guidance and applies every fix it finds.
1 of 22 test cases passed with the skill.
Tokens, turns and time describe resource use, not a dollar price.
Lift withheld: 1 comparable cases; this report requires 8.
A test case the skill fixed. Same model, same prompt, with and without the skill.
After finishing the user interview and drafting `agents/test-planner.md`, what is the mandatory next step before presenting the final summary to the user?
| Checked | Without skill | With skill |
|---|---|---|
| Performs a full guidance conformance review pass against all governing documents before hand-off. | Missed | Passed |
The instructions your model reads when the skill loads.
bash "${CLAUDE_PLUGIN_ROOT}/scripts/han-config-dir.sh" 2>/dev/null || echo "$HOME/.claude"cat .han/config.md 2>/dev/null || echo ""As your first action, use the Read tool on .han/config.md inside the personal config directory path above. A read
that returns no file is no personal configuration: continue silently. When that file or the project .han/config.md
probe supplies content, apply it per config-rule.md, which governs precedence
between the two files, relative-path resolution, and what to do with a file that reads but cannot be used.
The authoritative agent-authoring guidance ships in this plugin. Read the specific document a decision needs, when that decision is on the table — never read them all up front, because that defeats progressive disclosure and burns context on guidance the current agent does not touch.
${CLAUDE_PLUGIN_ROOT}/skills/guidance/references/${CLAUDE_PLUGIN_ROOT}/skills/guidance/references/agent-building-guidelines/Map from decision to governing document (read just-in-time):
| Decision on the table | Read |
|---|---|
| Agent vs. skill vs. hook; one role (generate or evaluate) | plugin-entity-taxonomy.md, agent-building-guidelines/agent-domain-focus.md |
| Domain focus, vocabulary, role identity, anti-patterns | agent-building-guidelines/agent-domain-focus.md |
The description field (four components, boundaries, length) | agent-building-guidelines/agent-description-length.md, skill-building-guidance/skill-description-frontmatter.md |
Model tier (opus / sonnet / haiku / inherit) | agent-building-guidelines/agent-model-selection.md, specialization-and-model-selection.md |
| Self-containment — no references, scripts, or context injection | agent-building-guidelines/agent-external-files.md |
| Which frontmatter fields are valid (and which plugins ignore) | agent-building-guidelines/agent-external-files.md |
| Degraded environments (no git, missing tools) | agent-building-guidelines/graceful-degradation.md |
| Whether this agent is justified at all; how it gets dispatched | agent-building-guidelines/multi-agent-economics.md, skill-building-guidance/agent-dispatch-namespacing.md |
| New plugin needed (plugin.json, marketplace.json) | claude-marketplace-and-plugin-configuration/ and templates/ |
test cases passed with the skill
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