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Run: 2026-10-09-01M4FYY12RY5921BZCWQ4RZ7X3
Run Details
Model:
Claude Haiku 5.5 (Reasoning, Low)
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
12.4s
Cost:
$0.001266
Provider:
Claude Platform on AWS
Evaluation summary
Score
Evaluator
Details Link
93.44%
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 relentless rain fell steadily over Ashford Manor on the cold night Lord Thorne was found dead in his study. Inspector Mabel Greaves arrived at half past eleven, her umbrella dripping onto the polished oak floorboards of the hallway. Nobody in the household had heard a single gunshot, though three guests swore they saw lanterns moving outside after midnight. Every suspect had a motive, and every motive, Greaves suspected, had been carefully hidden behind practiced, courteous smiles for years. Greaves removed her gloves, knelt beside the body, and noticed the brass key clutched tightly in its cold right hand. Somewhere in the house, a clock struck midnight, and then the housekeeper began to scream uncontrollably from the upstairs landing.
created_at
"2026-10-09T09:12:00.355Z"
10/9/2026, 9:12:00 AM
model
"anthropic/claude-haiku-5.5-20261007"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
2008
moderation_latency
(null)
generation_time
12364
tokens_prompt
46
tokens_completion
456
native_tokens_prompt
62
native_tokens_completion
2519
native_tokens_completion_images
(null)
native_tokens_reasoning
2260
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
0.0012657
router
(null)
user_agent
"langchainjs-openai/1.0.0 ((node/v24.21.0; linux; x64))"
http_referer
(null)
request_id
"req-1791537120-n0crthTMViFFgMTyD0ZI"
session_id
(null)
preset_id
(null)
api_type
"completions"
id
"gen-1791537120-0GYEvFXOkwX7nG5mTAbw"
upstream_id
"msg_011CfrQSuwModDGTRW5rMMQG"
provider_responses
0
endpoint_id
"b6cdf493-3a61-441f-a134-e7944fddb980"
id
"msg_011CfrQSuwModDGTRW5rMMQG"
is_byok
false
latency
728
model_permaslug
"anthropic/claude-haiku-5.5-20261007"
provider_name
"Claude Platform on AWS"
status
200
total_cost
0.0012657
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
93.44%
Matches word count
n/a
neededClean
false
sentences
6
wordCounts
0
20
1
19
2
20
3
20
4
20
5
20