# Ministral 3 vs Gemma 4: reasoning history rules differ

Compare Ministral 3 and Gemma 4 reasoning-history rules, separating ordinary completed turns from tool continuations and final-answer fields.

Author: Retrivium team
Updated: 2026-11-03
Canonical URL: https://retrivium.ai/journal/ministral3-vs-gemma4-thinking-history/
Language: en

Reasoning history is model-specific. A policy that follows Ministral 3 guidance can conflict with Gemma 4 guidance if it is applied indiscriminately to every completed assistant turn.

## Read the recommendations separately

The [Ministral 3 Reasoning card](https://huggingface.co/mistralai/Ministral-3-8B-Reasoning-2512/raw/main/README.md) recommends keeping reasoning traces in multi-turn context. The [Gemma 4 card](https://huggingface.co/google/gemma-4-26B-A4B-it/raw/main/README.md) says ordinary historical model turns should contain the final response, with thinking preserved for tool-call turns as an exception.

The [Gemma thinking guide](https://ai.google.dev/gemma/docs/capabilities/thinking) documents thinking behavior and output channels. These sources describe their own models. They should not be reduced to a universal claim that all reasoning must always be retained or always removed.

## Distinguish a new question from tool continuation

Imagine a model solving a small fictional calculation. It reasons, requests a calculator result and continues after the tool returns. Later, the user asks a separate question based on the final answer.

The tool continuation belongs to an unfinished interaction. The later user question begins a different ordinary turn. Treating both boundaries identically can preserve content a model does not expect or remove content needed for the ongoing tool sequence.

## Build a history-policy map

| Conversation material | Question for the selected model |
| --- | --- |
| Earlier final answer | Is it still present as user-visible context? |
| Earlier ordinary reasoning | Does the model guidance retain or omit it? |
| Current tool reasoning | Is the continuation context preserved? |
| Tool observation | Is it associated with the correct call? |
| New user message | Does it begin the intended next turn? |

This map concerns structured conversation construction. It does not require exposing reasoning to the end user, and display formatting alone does not prove which content was returned to generation.

## Inspect the transformation itself

Keep a small before-and-after message fixture for each family. Compare raw model output, parsed final answer and the next request's history. Look for accidental loss of final text when removing thought channels.

A wrapper that summarizes reasoning has introduced another transformation. It should not be called faithful preservation merely because the summary is shorter. Likewise, a universal regular expression that removes everything after an opening marker can erase the answer as well as reasoning.

## Evaluate the intended continuation

Use a checked follow-up task whose correct answer depends on the prior final result. For the tool case, require the returned observation. For the ordinary case, require the supplied conversation facts.

The useful outcome is a family-specific history policy with a reproducible fixture and accepted continuation. It does not show that longer histories are always better or that one family's rule is superior in general. Repeat the policy check after a checkpoint or template update rather than assuming that similar field names imply identical semantics.

## Related reading

- [Keep tokenizer vocabulary, special tokens and chat templates in one release](/journal/tokenizer-artifact-release-manifest/)
- [Validate reasoning and answer boundaries in vLLM parser output](/journal/vllm-reasoning-parser-boundaries/)