← The Index / devtools
Scored by model · 3 samples, median · No human review
Rank 114 of 128 · clearer than 9% of the index, 8% of devtools · Reviewed 2026-10-12
Coasty
coasty.ai
· devtools
56
GRADE C
Ranked by what each change is worth on the composite — the gap to the next rung of the ladder times the dimension’s weight. Computed from the scores, not written by the model; the model’s sentence under each is the action.
Add a concrete product noun naming what Coasty sells, e.g., 'live-desktop evaluation suite' for computer-use agents.
Show a concrete, testable outcome or metric, such as 'outcomes graded with full traces' or an OSWorld score.
Use a plain product noun instead of arena or generic terms, e.g., 'live-desktop evaluation suite'.
All three together: 56 → 67. Every dimension one rung up: 71 (grade B). Ceiling is 95.
Built only from facts already on the page — not the company’s words. Shown so the gap between what was written and what could have been written is concrete rather than a number.
Five alternative headlines in five angles, a subhead, a call-to-action line, and a line-by-line edit for each of the five dimensions — written only from facts already on coasty.ai, gated like a rating (anything with a struck word is dropped, not sold). Delivered on a private page in about a minute.
Five dimensions on one ladder — 5 · 20 · 35 · 50 · 65 · 80 · 95 — weighted clarity 30%, specificity 20%, jargon 20%, proof 15%, call to action 15%. For each: the rung the page matched, the words that drove it, and what would reach the next rung. Full rubric →
The headline is not a concrete product noun but hints at a marketplace-like arena.
The open arena for computer use.
Next rungAdd a concrete product noun naming what Coasty sells, e.g., 'live-desktop evaluation suite' for computer-use agents.
No numbers or measurable outcomes in the headline.
The open arena for computer use.
Next rungShow a concrete, testable outcome or metric, such as 'outcomes graded with full traces' or an OSWorld score.
Uses the abstract term 'arena' without a clear product category.
The open arena for computer use.
Next rungUse a plain product noun instead of arena or generic terms, e.g., 'live-desktop evaluation suite'.
No customer names, logos, or numeric proof on this snippet.
Nothing on the page addresses this.
Next rungInclude verifiable proof such as a public benchmark or a named metric (e.g., OSWorld score) and its value.
Multiple CTAs present, but not tied to a concrete product statement in the headline.
Book a meeting Book a meeting
Next rungPlace a low-friction CTA like 'Book a meeting' directly under a concrete product statement.
The open arena for computer use.Clear statement from the page used as the basis for clarity/jargon scoring.
Backed by Backed by Y Combinator Combinator The full stack of computer use. We run coarena.ai, the open leaderboard for computer-use agents. We build the real-world environments behind it. And our own computer-use models train on the same infrastructure. We do the whole thing. Book a meeting Book a meeting Visit coarena.ai Visit coarena.ai MATCHUP — LIVE Task: reconcile the June ledger in the ERP. gpt-5.6 PASS · 41 steps fable-5 PASS · 52 steps astra Running… Blind. Outcome-graded. Reproducible. 0.0 % Best OSWorld run on our harness OSWorld-Verified, public Full OSes — Windows & Linux Steps of long-horizon budget The problem The problem The frontier is graded on stale benchmarks, cherry-picked demos, and toy VMs. Benchmarks saturate Public suites leak into training data. Scores keep climbing while real capability doesn't. Demos aren't evidence A polished clip proves one run on one happy path. Labs and buyers need the failure modes. Toy environments don't transfer Static snapshots of stripped-down apps reward memorization, not the mess of real software. The solution The solution Evaluation you can trust Agents are dropped into real operating systems with real software and graded on outcomes — blind, traced, and reproducible. We run every layer ourselves, on the same production infrastructure our own models train on. Live head-to-head arena at coarena.ai Real Windows and Linux desktops, real apps Our own production-grade models on the same stack Outcome grading w
Strongest: Call to action 80. Weakest: Proof 20. The 3 passes agreed within 9 points.
Badges are issued to grades A and B. The share card for this page shows the headline with its jargon struck through; paste the URL anywhere that unfurls links.
Scored from the live homepage
on 2026-10-12 by gpt-5-nano,
3 independent passes, median taken.
Page snapshot 5d05e003fb93.
Rubric 5abbca9a (current; what it says).
No person reviewed or edited this score. If the rubric and the score disagree, the rubric wins
and the page is re-scored — not hand-corrected.
Re-scored when the homepage text changes.