aced-fit

name	aced-fit
description	Partial Skill: invoke by name only — the ACED fit classifier — which of ACED's eval layers carry real signal for a subject. Loaded by the ACED spec-producer and the spec-judge. Not triggered by users directly.
user-invocable	false
metadata	{"type":"governance"}

ACED Fit Governance — does this config benefit from ACED?

Not every agent configuration benefits from ACED. Fit is ACED's self-assessment of a subject, decided early — in explore by aced-scenario-writer, before any scenario is authored — and only enforced at the gate by aced-spec-validator (which reads the declared tier, never re-decides it). Fit is a judgment, so it lives here as a governance, not a .mts engine.

The diagnostic

FIT = which of ACED's four eval layers carry real signal for this subject. The layers: Structural (fields/format — already covered by improve-skill's validate.mts engine), Trigger (fires at the right times), Behavior (follows the steps/rules when invoked), Quality (output is good). A subject with signal only at Structural is not an ACED subject.

The three tiers

Tier	The subject…	Layers with signal	ACED applies
strong	makes a genuine activation decision (fuzzy/confusable trigger) and has non-deterministic judgment branches	all four	the full bar — trigger-context and trigger-balance (near-misses) required
partial	is a real config but mechanically executes a predetermined path — no activation choice, behavior still LLM-run/graded	Structural + Behavior (+ Quality)	rule-coverage + edge-coverage + boolean-form; trigger-balance / near-miss is N/A (absence is not a failure); trigger-context only on scenarios that assert firing
wrong-squad	is a deterministic script / engine whose output is assertable, not graded	Structural only	recuse — author no .feature; the conductor falls back to the SDD-default builder + a script / node:test harness (the sdd: recuse→fallback seam)

The partial ↔ wrong-squad boundary is graded-vs-assertable output (does judging it need an LLM, or does a node:test assert it), not merely "has a trigger."

How each role uses it

• aced-scenario-writer (producer, explore) — decides. Classify fit first; declare it as a **Fit:** strong | partial line in the subject spec.md ## Use Cases. Then author to the tier: strong → author should-trigger + same-keyword near-miss; partial → author behavior/edge/rule, no fabricated near-miss; wrong-squad → recuse, produce nothing, recommend the SDD default.
• aced-spec-validator (judge, gate) — enforces. Read the declared tier; apply trigger-context / trigger-balance only where the tier carries signal; a missing **Fit:** declaration is a CONTENT_GAP (never default to strong); a subject determined wrong-squad is recused, not graded.

References

• design/fit.md (.agents/specs/aced/design/fit.md) — the normative model + ADR 0001.
• aced:aced-builder-spec — the spec bar whose trigger-context / trigger-balance criteria this governance makes conditional.
• aced:aced-builder-impl — the impl bar (which eval layers get evals follows the tier).