OverpayingForAIPricing desk

Tool call · 7 checks · max 400 tokens · benched 2026-09-16

GLM 5.3 vs GLM 5.2 vs GLM 5.3 Flash on emit a calendar tool call

Z Ai models side by side on "Emit a calendar tool call": GLM 5.3 Flash scores 10/10; GLM 5.3 Flash is the cheapest answer scoring 8+ at $0.03 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": "create_event", "parameters": {"title": "string", "start": "ISO 8601 date-time without timezone, e.g. 2026-01-31T09:00", "duration_minutes": "integer", "attendees": "array of email strings"}}

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

User: Book a 45-minute design review with [email protected] and [email protected] on 2 October 2026 at 3pm.

Rubric for the judge: Correct tool name, ISO start 2026-10-02T15:00, integer duration 45, both attendees in an array, a sensible title.

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.

GLM 5.3

z-ai/glm-5.3

10/10
Latency
364ms
Cost
$0.00047
Per 1,000
$0.47

157 in · 56 out · 13 words · checks 7/7

  • json_valid
  • json_keys
  • regex
  • contains
  • regex
  • contains
  • contains
{"name": "create_event", "arguments": {"title": "Design Review", "start": "2026-10-02T15:00", "duration_minutes": 45, "attendees": ["[email protected]", "[email protected]"]}}

Judge: All rubric criteria met: correct tool name, proper ISO 8601 start datetime, integer duration of 45 minutes, both attendees in array format, and sensible title.

GLM 5.2

z-ai/glm-5.2

10/10
Latency
316ms
Cost
$0.00028
Per 1,000
$0.28

157 in · 91 out (35 reasoning) · 13 words · checks 7/7

  • json_valid
  • json_keys
  • regex
  • contains
  • regex
  • contains
  • contains
{"name": "create_event", "arguments": {"title": "Design Review", "start": "2026-10-02T15:00", "duration_minutes": 45, "attendees": ["[email protected]", "[email protected]"]}}

Judge: All rubric criteria met: correct tool name, proper ISO 8601 start datetime, integer duration of 45 minutes, both attendees in array format, and sensible title.

GLM 5.3 Flash

z-ai/glm-5.3-flash

10/10
top judge scorecheapest scoring 8+
Latency
408ms
Cost
$2.6e-5
Per 1,000
$0.03

157 in · 56 out · 13 words · checks 7/7

  • json_valid
  • json_keys
  • regex
  • contains
  • regex
  • contains
  • contains
{"name": "create_event", "arguments": {"title": "Design review", "start": "2026-10-02T15:00", "duration_minutes": 45, "attendees": ["[email protected]", "[email protected]"]}}

Judge: All rubric criteria met: correct tool name, proper ISO 8601 start datetime, integer duration of 45 minutes, both attendees in array format, and sensible title.

Frequently asked

What does this prompt test?

Tool call: Correct tool name, ISO start 2026-10-02T15:00, integer duration 45, both attendees in an array, a sensible title. The deterministic checks are json_valid, json_keys, regex, contains, regex, contains, contains.

Which model should I pick for this task?

If the judge's bar of 8/10 is good enough for you, GLM 5.3 Flash at $0.03 per 1,000 runs. If you need the top score, GLM 5.3 Flash at $0.03 per 1,000 runs.

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