[MODEL] Claude verbose code comments by default — ignores instructions to stop.

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Type of Behavior Issue

Claude modified files I didn't ask it to modify

What You Asked Claude to Do

Description

Claude Code adds far too many code comments by default. The comments are mostly redundant, restating what the adjacent code already makes obvious. It happens on every language, every model.

Crucially, this default persists even when explicitly told to stop:

• A clear, mandatory rule in CLAUDE.md does not reliably suppress it.
• Reinforcing the rule via the memory system does not stop it either.

I suppose the core problem is that verbose commenting is the out-of-the-box default, and that default is strong enough to override explicit user instructions. Users shouldn't have to stack a CLAUDE.md rule + memory entries + enforcement hooks just to get clean code.

Environment

• Claude Code
• Model: claude-opus-4-8

What Claude Actually Did

Contant verbose code commenting.

Expected Behavior

Expected behavior

Restrained commenting as the default — comment only genuinely non-obvious constraints or "why" decisions, not self-evident "what." And when a project instruction says to minimize comments, that instruction should be reliably respected.

Actual behavior

Reflexive explanatory comments on most code output, even when instructed otherwise. Requires constant manual cleanup .

Files Affected

all

Permission Mode

Accept Edits was ON (auto-accepting changes)

Can You Reproduce This?

Yes, every time with the same prompt

Steps to Reproduce

_No response_

Claude Model

Opus

Relevant Conversation

Impact

High - Significant unwanted changes

Claude Code Version

2.1.17

Platform

Anthropic API

Additional Context

_No response_