| name | askit-build-subagent |
| description | Creates and improves Claude subagents (agents/<name>.md) to the Advanced Skill Library Standard. Use when you need to author a new subagent, scaffold an agents/ delegate, declare its tools and chain, or raise an existing subagent's conformance. |
| metadata | {"version":"0.1.0","tier":"universal","audience":"intermediate"} |
askit-build-subagent
Purpose
Author conformant subagents. Two modes: create scaffolds a new agents/<name>.md (frontmatter + role body); improve raises an existing subagent toward the quality bar. Subagents are Claude-only for plugin distribution (Codex v0.135 plugins cannot ship [agents.*]; Standard sec 3.3), so this skill emits no Codex artifact. Authoring depth is in references/authoring-subagents.md.
When to use
When the user asks to create, scaffold, write, or improve a subagent (an agents/<name>.md delegate).
create mode
- Brief interview: ask for the subagent name (kebab-case), the bounded job it owns, the narrowest tools it needs, and which components (if any) it may invoke. Skip the interview if these inputs are already in context.
- Copy
templates/agent.md into agents/<name>.md.
- Fill the frontmatter:
name equal to the file basename; a description that states what AND when (Standard sec 8.1); tools as the narrowest set (sec 9); optional model; chain listing components it may invoke (omit if none); metadata.version, metadata.tier, metadata.status, and metadata.agent-targets: [claude] (sec 3.3 - subagents are Claude-only for plugin distribution).
- Register the subagent in
library.json components.subagents as { name, path, version, tier, status }.
- If the subagent declares a
chain, add the entry to agents/_chain-permitted.yaml (<name>: [<invoked>, ...]) so S4 has no orphan.
- Assess with
node scripts/evaluate.mjs . --json and iterate until 0 errors (S3 components index + S4 chain contract must be clean).
improve mode
- Run
node scripts/evaluate.mjs . --json and read the report.
- For each finding: an S3 error -> declare/undeclare the subagent in
components.subagents to match disk; an S4 orphan -> add the missing caller -> callee to agents/_chain-permitted.yaml; an S4 phantom (the contract names a component not on disk) -> remove that contract entry, fix a misspelled name, or create the missing component. For any other finding, read its message and apply the fix it states.
- Re-run evaluate to confirm.
Scope
Claude-only: a subagent is agents/<name>.md (Claude auto-discovers it). Codex does not ingest plugin-shipped subagents (Standard sec 3.3), so there is no Codex render. Authoring is performed inline by the running agent; the toolkit's own askit-skill-author subagent is the delegated authoring role for skills.