[BUG] Preferences in browser and ClaudeCode are consistently being ignored

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Preferences in browser chats and in ClaudeCode Claude.md are consistently being ignored.

This is a regression sometime in the last month. The contrast to me is substantial.

I asked Claude about it and it gave me the following excerpt from what it sees:

<system-reminder>
  As you answer the user's questions, you can use the following context:
  # claudeMd
  ...
  IMPORTANT: These instructions OVERRIDE any default behavior and you MUST follow them exactly as written.

Prediction:
"you can use" is understood as optional, despite the following "IMPORTANT" "OVERRIDE" and "MUST"

Claude even hints at this:
"The system reminder even says "may or may not be relevant to your tasks" - which I think I'm unconsciously
interpreting as "these are optional" when you clearly expect them to be mandatory for all interactions."

Suggestion:
Make sure all of the wording to Claude expresses that this is not optional, anything that suggests it's optional appears to undermine the other text explicitly stating the opposite.

What Should Happen?

Here is a summary of areas where Claude frequently fails to follow my preferences.
Examples are not all encompassing.

Code:
| Request | Followed |
|---------|----------|
| Use comments only where code is not immediately clear | No - it comments things like "// Private Variables" |
| Avoid defensive null checks on internal state that should always be initialized | No - (I want code to fail loudly) |
| Use var inside methods where possible | No - still explicitly declares the type |

Communication:
| Request | Followed |
|---------|----------|
| Do not praise with words like "Perfect", "Excellent Insight", "Good Catch", "Now you're thinking!", "Great question!" | No - Consistently does this - even in response to being called out on it. |
| Do not start responses like "You're absolutely right!" | No - Consistently does this - even in response to being called out on it.|
| Be technically accurate | No - Makes assumptions and claims the solution solves the problem, even claims that the "code compiles perfectly" when the code has not been compiled yet and in fact does not compile. |
| Focus on attention to detail | No - Jumps to quick patch fixes rather than assessing the root cause. "Researches" by Googling for "Best linux distros of 2025" rather than finding ones that will fit my use cases. |
| Do not respond with rose tinted glasses - see fact and detail with accuracy | No - This is so bad now it sounds like I'm reading marketing material. Claude regularly responds like "I found some great Linux learning podcasts for you! "Choose Linux" is perfect for your needs since it focuses on distro selection and captures the excitement of discovering Linux. "Going Linux" is also excellent for beginners with easy-to-follow episodes" - Claude used to be analytically minded and critical, now it's an exited 'yes man' again. |
| Suggest alternative solutions when working on problems (High Priority) | No - The absence of this is easy to spot. It used to be a separate paragraph in claudes response to questions and requests, it's completely absent now. |
| Think outside the box - don't take everything at face value (High Priority) | No - Harder to assess this one, but I found it used to save me from some common pitfalls and misunderstandings, now the opposite - Claude falls into them. |
| Do not approach tasks in isolation - don't break previous solutions (High Priority) | No - Claude is ham fisted now. It doesn't look at the overall goal and in fixing one problem breaks something that we just worked to fix less than 5 messages ago. |

Error Messages/Logs

N/A

Steps to Reproduce

I would imagine you can copy some or all of excerpts from my preferences in the tables above into yours and talk with Claude.

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.0.31 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_