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Run: 2026-09-23-01M37P9GBCANWT5AEK2GAEWT83
Run Details
Model:
Claude Opus 5.5 (Reasoning)
Test:
N-Length Sentences
Scenario:
Write sentences with 10 words each
Duration:
18.1s
Cost:
$0.036248
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 10 words. Please make sure that each sentence has the same length. Only return the opening itself.
Model response
Messages
Meta
AI
The storm arrived at Blackwood Manor just after midnight struck. Lightning split the sky above the old stone chapel roof. Inside, eight guests gathered nervously around the dying fireplace embers. Nobody had seen Lord Ashford since dinner ended hours ago. His wife, Margaret, insisted that he had simply gone walking. But no sane man would walk through such violent rain. The butler, Graves, stood silently beside the tall library door. His gloved hands trembled slightly, though his face remained calm. Then a scream echoed down from the east wing corridor. Everyone rushed upstairs, candles flickering wildly in the cold draft. The young maid, Elsie, pointed toward the open study door. Lord Ashford lay sprawled across his desk, his eyes open. A silver letter opener protruded from beneath his left shoulder. Margaret did not scream; she only whispered one strange word. Somewhere below, the grandfather clock began to chime three times. And every guest realized the killer was standing among them.
created_at
"2026-09-23T17:51:21.98Z"
9/23/2026, 5:51:21 PM
model
"anthropic/claude-opus-5.5-20260921"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
4158
moderation_latency
(null)
generation_time
18098
tokens_prompt
46
tokens_completion
504
native_tokens_prompt
62
native_tokens_completion
1800
native_tokens_completion_images
(null)
native_tokens_reasoning
1461
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
0.036248
router
(null)
user_agent
"langchainjs-openai/1.0.0 ((node/v24.20.0; linux; x64))"
http_referer
(null)
request_id
"req-1790185881-q4HKDQOdbLO9TkQ8klc6"
session_id
(null)
preset_id
(null)
api_type
"completions"
id
"gen-1790185881-SWL3GCiZdI2hFYkIUSfT"
upstream_id
"msg_011CfLo7KTiso75EXj4QguWU"
provider_responses
0
endpoint_id
"3a2388bc-3740-4e64-a1f5-4e301726b6b9"
id
"msg_011CfLo7KTiso75EXj4QguWU"
is_byok
false
latency
1270
model_permaslug
"anthropic/claude-opus-5.5-20260921"
provider_name
"Claude Platform on AWS"
status
200
total_cost
0.036248
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
16
wordCounts
0
10
1
10
2
10
3
10
4
10
5
10
6
10
7
10
8
10
9
10
10
10
11
10
12
10
13
10
14
10
15
10