slate-ar-fast

description	Slate v2 fastest-safe mini-skill. Picks or creates the hottest perf target, runs slate-ar-perf with no-regression checks, and stops at target, plateau, or correctness blocker.
argument-hint	[optional perf surface]
disable-model-invocation	true
name	slate-ar-fast
metadata	{"skiller":{"source":".agents/rules/slate-ar-fast.mdc"}}

Slate AR Fast

Handle $ARGUMENTS.

Use this when the user says "make it fast", "fastest", "perf", or wants the agent to pick the highest-value Slate v2 performance target.

This is an expert override. The normal broad workflow is slate-ar-perfect <surface>, which may call this internally.

Contract

Load slate-ar-status first.

If $ARGUMENTS names a specific target or surface, run slate-ar-perf on that target. If the target is missing but specific, slate-ar-perf should create the benchmark target and correctness contract.

If no target is named, pick the hottest target from current evidence:

1. user-visible behavior latency first;
2. regression versus legacy next;
3. broad architectural fanout next;
4. noisy raw microbenchmarks last.

Bare slate-ar-fast means fastest-safe loop, not a one-off benchmark probe. Use autogoal unless the user explicitly says probe, status, or asks for a single read-only measurement.

The goal should target one primary metric and one correctness contract. If no target is named, choose the hottest target and record why.

No-Regression Rule

Every kept perf packet needs correctness evidence. If selection, typing, copy, paste, undo, IME, focus, cursor placement, or follow-up input regresses, log the packet as checks_failed or route to slate-patch.

If correctness coverage is missing, create or route to the missing oracle before optimizing. Do not make the metric faster by weakening behavior, delaying input, or hiding work behind debounce.

Stop Rules

Stop when one of these is true:

• target threshold is met with checks green;
• legacy parity is met where legacy is the comparison;
• three correctness-green packets improve the primary metric by less than 5%;
• the next safe win needs slate-plan;
• behavior correctness blocks further perf work.

Handoff

Report target, benchmark command, primary metric, baseline/latest/best, checks, kept/discarded/checks-failed packets, and next target.