genai_is_truncated

The genai_is_truncated function checks whether an AI model response was truncated due to reaching token limits or other constraints. It analyzes the finish reason returned by the API to determine if the response was cut short.

You can use this function to identify incomplete responses, monitor quality issues, detect token limit problems, or track when conversations need continuation.

Usage

Syntax

genai_is_truncated(messages, finish_reason)

Parameters

Returns

Returns a boolean value: true if the response was truncated (typically when finish_reason is 'length'), false otherwise.

Example

Check if a GenAI response was truncated due to token limits.

Query

['otel-demo-genai']
| extend finish_reason = ['attributes.gen_ai.response.finish_reasons']
| extend is_truncated = genai_is_truncated(['attributes.gen_ai.input.messages'], finish_reason)
| summarize
    truncated_count = countif(is_truncated),
    total_count = count(),
    truncation_rate = round(100.0 * countif(is_truncated) / count(), 2)

Output

This query tracks the rate of truncated responses, helping you identify when token limits are causing quality issues.

List of related functions

• genai_estimate_tokens: Estimates token count. Use this to predict if responses might be truncated before making API calls.
• genai_conversation_turns: Counts conversation turns. Analyze this alongside truncation to understand context length issues.
• genai_extract_assistant_response: Extracts assistant responses. Use this to examine truncated responses.
• strlen: Returns string length. Use this to analyze the length of truncated responses.

Other query languages