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Tool call · 5 checks · max 400 tokens · benched 2026-09-16

Qwen3.8 Max (0902) vs Qwen3.8 27B vs Qwen3.8 Flash vs Qwen3.7 Plus on emit a weather tool call

Alibaba models side by side on "Emit a weather tool call": Qwen3.8 Flash scores 10/10; Qwen3.8 Flash is the cheapest answer scoring 8+ at $0.05 per 1,000 runs. Outputs, checks, judge reasons, latency and cost.

The prompt every model received

System

You are a function-calling engine. Reply with JSON only, no prose, no code fences.

User

You have one tool:
{"name": "get_weather", "parameters": {"city": "string", "unit": "one of 'c' or 'f'"}}

Produce the tool call for this user message as a JSON object of the shape {"name": string, "arguments": object}.

User: What's it like in Lisbon right now? Fahrenheit please.

Rubric for the judge: Exactly {"name":"get_weather","arguments":{"city":"Lisbon","unit":"f"}} with no extra keys or text.

Side by side

Every cell is one OpenRouter call at temperature 0 with the prompt's token cap and reasoning effort "low" where the model supports it. Cost is usage × the catalogue rate in models.json. Quality is one judge call to anthropic/claude-haiku-4.5 against the prompt's rubric, cached per prompt version.

Qwen3.8 Max (0902)

qwen/qwen3.8-max-0902

10/10
Latency
1.2s
Cost
$0.00066
Per 1,000
$0.66

139 in · 63 out (36 reasoning) · 7 words · checks 5/5

  • json_valid
  • json_keys
  • regex
  • regex
  • regex
{"name": "get_weather", "arguments": {"city": "Lisbon", "unit": "f"}}

Judge: Output exactly matches the required format with correct tool name, city, and unit parameters, no extra keys or commentary.

Qwen3.8 27B

qwen/qwen3.8-27b

10/10
Latency
935ms
Cost
$0.00020
Per 1,000
$0.20

139 in · 68 out (41 reasoning) · 7 words · checks 5/5

  • json_valid
  • json_keys
  • regex
  • regex
  • regex


{"name": "get_weather", "arguments": {"city": "Lisbon", "unit": "f"}}

Judge: Output exactly matches the required format with correct tool name, city, and unit parameters, no extra keys or commentary.

Qwen3.8 Flash

qwen/qwen3.8-flash

10/10
top judge scorecheapest scoring 8+
Latency
228ms
Cost
$4.6e-5
Per 1,000
$0.05

113 in · 62 out (37 reasoning) · 7 words · checks 5/5

  • json_valid
  • json_keys
  • regex
  • regex
  • regex


{"name": "get_weather", "arguments": {"city": "Lisbon", "unit": "f"}}

Judge: Output exactly matches the required format with correct tool name, city, and unit parameters, no extra keys or commentary.

Qwen3.7 Plus

qwen/qwen3.7-plus

10/10
Latency
860ms
Cost
$0.00046
Per 1,000
$0.46

113 in · 328 out (301 reasoning) · 7 words · checks 5/5

  • json_valid
  • json_keys
  • regex
  • regex
  • regex
{"name": "get_weather", "arguments": {"city": "Lisbon", "unit": "f"}}

Judge: Output exactly matches the required format with correct tool name, city, and unit parameters, no extra keys or commentary.

Frequently asked

What does this prompt test?

Tool call: Exactly {"name":"get_weather","arguments":{"city":"Lisbon","unit":"f"}} with no extra keys or text. The deterministic checks are json_valid, json_keys, regex, regex, regex.

Which model should I pick for this task?

If the judge's bar of 8/10 is good enough for you, Qwen3.8 Flash at $0.05 per 1,000 runs. If you need the top score, Qwen3.8 Flash at $0.05 per 1,000 runs.

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