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Run: 2026-09-29-01M3P2BJ7VX1MYWK26XEX9R6FK
Run Details
Model:
Claude Sonnet 5.5 (Reasoning)
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
12.9s
Cost:
$0.018624
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
Rain hammered the windows of Blackwood Manor the night Lord Aldrich Pemberton was found dead in his locked private study. Inspector Maren Cole arrived at midnight, soaked and irritated, carrying a battered notebook and very little patience for wealthy families. The butler, pale and trembling, led her down the corridor where portraits of dead ancestors watched every step she took. Pemberton lay slumped across his desk, one hand clutching a broken pocket watch stopped at exactly nine minutes past eleven. The door had been bolted from inside, the window sealed by painted shutters, and one key hung around his neck. Cole knelt beside the body and noticed a faint scent of bitter almonds lingering beside the nearly empty brandy glass. Someone in this house murdered him, she whispered, and everyone beneath its roof had good reason to want him gone.
created_at
"2026-09-29T07:51:34.401Z"
9/29/2026, 7:51:34 AM
model
"anthropic/claude-sonnet-5.5-20260928"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
4166
moderation_latency
(null)
generation_time
12836
tokens_prompt
46
tokens_completion
436
native_tokens_prompt
62
native_tokens_completion
1850
native_tokens_completion_images
(null)
native_tokens_reasoning
1563
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
0.018624
router
(null)
user_agent
"langchainjs-openai/1.0.0 ((node/v24.21.0; linux; x64))"
http_referer
(null)
request_id
"req-1790668294-HelQNjH3UtbG4MLTsi7x"
session_id
(null)
preset_id
(null)
api_type
"completions"
id
"gen-1790668294-3MppT6alzmlHzm7vK4gc"
upstream_id
"msg_011CfXNE1yapLnxBY9Ah8B6V"
provider_responses
0
endpoint_id
"99aaad94-923b-4fc1-b763-271ed5486f7a"
id
"msg_011CfXNE1yapLnxBY9Ah8B6V"
is_byok
false
latency
770
model_permaslug
"anthropic/claude-sonnet-5.5-20260928"
provider_name
"Claude Platform on AWS"
status
200
total_cost
0.018624
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