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Run: 2026-09-29-01M3P2EX0FYCKX74YAJ5Y6SH7V
Run Details
Model:
Claude Sonnet 5.5 (Reasoning)
Test:
N-Length Sentences
Scenario:
Write sentences with 20 words each
Duration:
14.8s
Cost:
$0.022994
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 discovered dead in his locked private study. Inspector Mara Quinn arrived at midnight, her boots soaked, her patience thinner than the cheap umbrella she had abandoned outside. Seven guests huddled in the drawing room, each wearing the same pale expression of people who had rehearsed their innocence. The butler, a stooped man named Hollis, led her upstairs without speaking, his candle trembling against the long, crawling shadows. Lord Pemberton lay slumped across his desk, one hand outstretched toward a teacup that still steamed faintly in the lamplight. Quinn noticed three things immediately: the bolted door, the open window, and the dry floor beneath it despite the storm. She knelt beside the body and caught a bitter almond scent that made her stomach tighten with old, familiar dread. Behind her, Hollis cleared his throat and whispered that the master had received a mysterious, unsigned letter just before dinner. Quinn rose, studied the ashes smoldering in the fireplace, and found one scorched corner of paper bearing a single initial. Downstairs, someone screamed, and the entire manor plunged into darkness, as though the house itself wanted to keep its secrets.
created_at
"2026-09-29T07:53:23.733Z"
9/29/2026, 7:53:23 AM
model
"anthropic/claude-sonnet-5.5-20260928"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
3866
moderation_latency
(null)
generation_time
14812
tokens_prompt
46
tokens_completion
554
native_tokens_prompt
62
native_tokens_completion
2287
native_tokens_completion_images
(null)
native_tokens_reasoning
1857
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
0.022994
router
(null)
user_agent
"langchainjs-openai/1.0.0 ((node/v24.21.0; linux; x64))"
http_referer
(null)
request_id
"req-1790668403-MdKMH33aLnVlo4i9yF2s"
session_id
(null)
preset_id
(null)
api_type
"completions"
id
"gen-1790668403-cAaBLL0uiAWh8bL5PzES"
upstream_id
"msg_011CfXNN55LGmiQtV56TyMn6"
provider_responses
0
endpoint_id
"99aaad94-923b-4fc1-b763-271ed5486f7a"
id
"msg_011CfXNN55LGmiQtV56TyMn6"
is_byok
false
latency
676
model_permaslug
"anthropic/claude-sonnet-5.5-20260928"
provider_name
"Claude Platform on AWS"
status
200
total_cost
0.022994
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
10
wordCounts
0
20
1
20
2
20
3
20
4
20
5
20
6
20
7
20
8
20
9
20