In my case it's been a strong no. Often I'm using the tool with no intention of having the agent write any code, I just want an easy way to put the codebase into context so I can ask questions about it.

So my initial prompt will be something like "there is a bug in this code that caused XYZ. I am trying to form hypothesis about the root cause. Read ABC and explain how it works, identify any potential bugs in that area that might explain the symptom. DO NOT WRITE ANY CODE. Your job is to READ CODE and FORM HYPOTHESES, your job is NOT TO FIX THE BUG."

Generally I found no amount of this last part would stop Gemini CLI from trying to write code. Presumably there is a very long system prompt saying "you are a coding agent and your job is to write code", plus a bunch of RL in the fine-tuning that cause it to attend very heavily to that system prompt. So my "do not write any code" is just a tiny drop in the ocean.

Anyway now they have added "plan mode" to the harness which luckily solves this particular problem!