Run: 2026-10-08-01M4DA8430TT1FF1CYZ4MGRB4X

Run Details

Model:
Claude Haiku 5.5 (Reasoning, Medium)
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
11.9s
Cost:
$0.001017
Provider:
Claude Platform on AWS

Evaluation summary

Score Evaluator
Details Link
92.13% Matches word count (details)

Model input

User/Human
Please write the opening scene of a murder mystery where each sentence has exactly 20 words. Please make sure that each sentence has the same length. Only return the opening itself.

Model response

AI
The rain had fallen on Ravensworth Manor for three days, and nobody inside it had slept soundly since the funeral. Detective Inspector Harriet Vane arrived at dawn, her coat soaked, her notebook already open and waiting in her gloved hand. Ten guests had been trapped in the house overnight, and the body of Edmund Croft lay still in the library. Every door had been locked from the inside, and every window was sealed shut against the howling storm outside tonight. Harriet knelt beside the corpse, noticed the single muddy footprint, and quietly asked who had touched the brandy glass beside him.
created_at"2026-10-08T08:32:02.153Z" 10/8/2026, 8:32:02 AM
model"anthropic/claude-haiku-5.5-20261007"
app_id182717
external_user(null)
streamedtrue
cancelledfalse
latency2980
moderation_latency(null)
generation_time11828
tokens_prompt46
tokens_completion417
native_tokens_prompt62
native_tokens_completion2021
native_tokens_completion_images(null)
native_tokens_reasoning1818
native_tokens_cached0
num_media_prompt(null)
num_input_audio_prompt(null)
num_media_completion0
num_search_results(null)
num_fetches(null)
web_search_engine(null)
origin"https://ncbench.com/"
is_byokfalse
finish_reason"stop"
native_finish_reason"end_turn"
service_tier"default"
usage0.0010167
router(null)
user_agent"langchainjs-openai/1.0.0 ((node/v24.21.0; linux; x64))"
http_referer(null)
request_id"req-1791448322-oHlpZ5NRi0xPMQCz0cFE"
session_id(null)
preset_id(null)
api_type"completions"
id"gen-1791448322-WKVJiSgjUWAUz52QZSFB"
upstream_id"msg_011CfpTbDYasrEByHBoov3Ah"
provider_responses
0
endpoint_id"b6cdf493-3a61-441f-a134-e7944fddb980"
id"msg_011CfpTbDYasrEByHBoov3Ah"
is_byokfalse
latency762
model_permaslug"anthropic/claude-haiku-5.5-20261007"
provider_name"Claude Platform on AWS"
status200
total_cost0.0010167
cache_discount(null)
upstream_inference_cost0
provider_name"Claude Platform on AWS"
response_cache_source_id(null)
data_region"global"
workspace_id"97e315e5-d303-487d-83c1-83180e8a13d4"

Evaluation details

Result Evaluator Details Meta Data
92.13% Matches word count n/a
neededCleanfalse
sentences5
wordCounts
020
120
220
320
421