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Run: 2026-10-09-01M4FXRJZV6S6CRJE28YMX0BPK
Run Details
Model:
Claude Haiku 5.5 (Reasoning, Low)
Test:
N-Length Sentences
Scenario:
Write sentences with 10 words each
Duration:
2.8s
Cost:
$0.000168
Provider:
Claude Platform on AWS
Evaluation summary
Score
Evaluator
Details Link
81.55%
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 rain fell hard on the silent old manor. Detective Helen Marsh stepped carefully through the muddy front gate. Officer Tom Briggs met her beneath the dripping stone archway. "The body was found in the library," he said quietly. Helen pulled on her gloves and followed him inside. Dusty portraits watched them from the cold, shadowed walls. A single lamp flickered weakly near the grand oak staircase. The victim lay sprawled across a faded Persian rug. Blood had pooled beneath his head in a dark circle. Helen knelt beside the body and studied the wound closely. "He was struck once, from behind, by someone standing close," she murmured. Briggs glanced nervously at the open window across the room. Someone had left in a hurry, and recently. On the desk lay a half-finished letter, its ink still wet. Helen lifted it carefully and began to read aloud. "If you are reading this, then I am already dead."
created_at
"2026-10-09T08:51:33.505Z"
10/9/2026, 8:51:33 AM
model
"anthropic/claude-haiku-5.5-20261007"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
2757
moderation_latency
(null)
generation_time
2757
tokens_prompt
46
tokens_completion
231
native_tokens_prompt
62
native_tokens_completion
324
native_tokens_completion_images
(null)
native_tokens_reasoning
0
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
0.0001682
router
(null)
user_agent
"langchainjs-openai/1.0.0 ((node/v24.21.0; linux; x64))"
http_referer
(null)
request_id
"req-1791535893-XFHnXg1sb1k1jg65dd9R"
session_id
(null)
preset_id
(null)
api_type
"completions"
id
"gen-1791535893-bXbLdMn86cBTA6XyqlNs"
upstream_id
"msg_011CfrNtUXPaBRczonQ2Ycns"
provider_responses
0
endpoint_id
"b6cdf493-3a61-441f-a134-e7944fddb980"
id
"msg_011CfrNtUXPaBRczonQ2Ycns"
is_byok
false
latency
698
model_permaslug
"anthropic/claude-haiku-5.5-20261007"
provider_name
"Claude Platform on AWS"
status
200
total_cost
0.0001682
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
81.55%
Matches word count
n/a
neededClean
false
sentences
16
wordCounts
0
9
1
10
2
10
3
10
4
9
5
9
6
10
7
9
8
10
9
10
10
12
11
10
12
8
13
11
14
9
15
10