Run: 2026-05-31-01KSYXPA4N7JE6T6AY67MBC83Q

Run Details

Model:: Claude Opus 4.8 (Reasoning, High)
Test:: N-Length Sentences
Scenario:: Write sentences with 10 words each
Duration:: 12.6s
Cost:: $0.030375
Provider:: Anthropic

Evaluation summary

Score	Evaluator	Details Link
100.00%	Matches word count	(details)

Model input

User/Human

Please write the opening scene of a murder mystery where each sentence has exactly 10 words.
Please make sure that each sentence has the same length. Only return the opening itself.

Model response

Rain fell hard against the windows of Blackwood Manor tonight.
Detective Sarah Cole arrived just before the storm grew worse.
The butler opened the door with a trembling, pale hand.
Inside, the guests had gathered near the cold stone fireplace.
Nobody spoke a single word about what happened that evening.
Upstairs, the lifeless body of Lord Harrington lay completely still.
A silver knife protruded from his chest, glinting dully there.
Sarah climbed the staircase slowly, dreading what awaited her there.
Every person downstairs had wanted this man dead for years.
One of them had finally chosen to make it happen.

Evaluation details

Result

Evaluator

Details

Meta Data

100.00%

Matches word count

n/a

neededClean

false

sentences

wordCounts

0	10
1	10
2	10
3	10
4	10
5	10
6	10
7	10
8	10
9	10