Custom Rovo Agent — LLM output truncation causes corrupted JSON in action inputs for large content

[Habib ZOUARI]

When a Forge custom Rovo Agent is asked to generate a large volume of structured content (e.g. a full course with multiple sections and components) in a single conversation turn, the LLM that powers the Rovo Agent silently truncates its output mid-generation. Because action inputs are constructed from the LLM's raw output, the truncated content results in malformed (non-parseable) JSON being passed to the action handler ,causing the action to fail or receive incomplete data. So i need to know if :

1. Is there an official, documented token/character limit on the LLM output that populates action inputs for Forge Rovo Agents?
2. Is there a plan to expose a structured truncation signal to action handlers?
3. Is there an alternative solution to maintain the generated large content with the same number of components?

[NewSysRS]

This is a classic 'Token Limit' issue. When Rovo generates a large JSON object, it hits the maximum output token threshold and simply stops mid-sentence, leaving the JSON string unclosed and 'corrupted.'
​To fix this, try these three strategies in your Agent's prompt or configuration:

​1. Explicitly Limit the Array Size
LLMs struggle to estimate how much space a JSON list will take. Add this to your System Prompt:

​"Limit your JSON output to a maximum of 10 items. If there are more, stop at 10 and do not attempt to summarize the rest within the JSON block."

​2. Use a 'Compacted' JSON Format
Ask the agent to strip whitespace to save tokens:
​"Output the JSON in a minified/compact format without extra spaces or newlines to maximize data density."

​3. The 'Validation' Prompt (The most effective fix)
Add this specific instruction to the end of your Agent's prompt:
​"Crucial: Ensure the JSON object is always syntactically correct and properly closed with } or ]}. If you run out of space, truncate the data items, but never truncate the closing syntax."

​4. Check for 'Nested' Blobs
If you are pulling in issue.description or comment.body, these often contain hidden characters or are too long. Use a smart value to limit the input text: {{issue.description.left(500)}} so the agent has more 'room' to write the JSON response.