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Run: 2026-10-09-01M4FXHCZ7XDK4S2V34H3JZ0TT
Run Details
Model:
Claude Haiku 5.5 (Reasoning, Low)
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
12.2s
Cost:
$0.001268
Provider:
Claude Platform on AWS
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 20 words. Please make sure that each sentence has the same length. Only return the opening itself.
Model response
Messages
Meta
AI
The rain had been falling over Ashford Manor since dawn, and nobody in the household had slept well that night. Detective Inspector Harold Finch arrived at half past seven, carrying an umbrella and a grim expression that suggested serious trouble. Lord Edmund Ashford lay motionless beside the library fireplace, a silver letter opener protruding from his chest like an accusation. Nobody had touched the body, according to the maid, who had screamed loudly enough to wake the entire sleepy village. Finch knelt beside the victim, noting the untouched teacup, the muddy boot prints, and the open window facing the gardens. Somewhere in this house, a killer had remained calm enough to tidy the study before the first light of dawn. Finch looked up at the assembled suspects and felt the familiar chill of certainty settle deep within his weary heart.
created_at
"2026-10-09T08:47:38.171Z"
10/9/2026, 8:47:38 AM
model
"anthropic/claude-haiku-5.5-20261007"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
2473
moderation_latency
(null)
generation_time
11953
tokens_prompt
46
tokens_completion
502
native_tokens_prompt
62
native_tokens_completion
2524
native_tokens_completion_images
(null)
native_tokens_reasoning
2245
native_tokens_cached
0
num_media_prompt
(null)
num_input_audio_prompt
(null)
num_media_completion
0
num_search_results
(null)
num_fetches
(null)
web_search_engine
(null)
origin
"https://ncbench.com/"
is_byok
false
finish_reason
"stop"
native_finish_reason
"end_turn"
service_tier
"default"
usage
0.0012682
router
(null)
user_agent
"langchainjs-openai/1.0.0 ((node/v24.21.0; linux; x64))"
http_referer
(null)
request_id
"req-1791535658-T19EYLlqPuHNdwBfkpsn"
session_id
(null)
preset_id
(null)
api_type
"completions"
id
"gen-1791535658-kUkdlaTpE7N6YNygJ56W"
upstream_id
"msg_011CfrNb8n1tQZid43eUF1YA"
provider_responses
0
endpoint_id
"b6cdf493-3a61-441f-a134-e7944fddb980"
id
"msg_011CfrNb8n1tQZid43eUF1YA"
is_byok
false
latency
841
model_permaslug
"anthropic/claude-haiku-5.5-20261007"
provider_name
"Claude Platform on AWS"
status
200
total_cost
0.0012682
cache_discount
(null)
upstream_inference_cost
0
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
100.00%
Matches word count
n/a
neededClean
false
sentences
7
wordCounts
0
20
1
20
2
20
3
20
4
20
5
20
6
20