code style: reduce lengthy AI comments

[must108]

A few merged PRs contain a lot of large "AI slop" type of comments. For example:
https://github.com/ClickHouse/clickhouse-go/pull/1922/changes#diff-70a5c3954aff99cd01e76bc970c6b027903c9fcbffffc205e9d040b9e31fbd50R14

Ideally, comments should never be this large.

Resolution Criteria

• Removal of existing AI slop comments
• Enhancement of AGENTS.md, specifying rules regarding comments
  • Comments should be 1-2 lines maximum, and detail blocks of code in a short and efficient way.
  • Comments should use ASD-STE100 Simplified Technical English (STE).
  • Comments should not refer to stakeholders in the real world. For example, if @must108 reviews a PR and asks for a specific enhancement, the comment should not mention him by name.
  • Comments should not refer to specific pull requests or commit IDs.
  • Feel free to edit this description to add more relevant rules!

Relevant PRs

#1829
#1833
#1834
#1921
#1922
#1923

[Laotree]

Instead of only removing existing AI-generated comments, introduce repository-level guidelines for AI-assisted development so that different AI tools and prompting styles produce more consistent contributions.

[kavirajk]

Agree. Right place to enforce this is AGENT.md I think.

I would like that changes in addition to removing the slop AI comments

[must108]

@Laotree @kavirajk I agree. I've updated description to include this

[Laotree]

AI-Assisted Development

AI-assisted contributions must follow the same engineering standards as human-written code.

• Keep changes narrowly scoped. Do not modify unrelated code, formatting, naming, or structure.
• Prefer existing patterns and abstractions. Do not introduce helpers, interfaces, wrappers, or abstractions without a clear benefit.
• Comments should explain why, constraints, invariants, or non-obvious behavior. Do not restate what the code already shows.
• Keep comments concise and use ASD-STE100 Simplified Technical English.
• Do not mention reviewers, contributors, issues, pull requests, commits, or other external stakeholders in source comments.
• Do not add generic or narrative comments that provide no information beyond the code.
• Validate AI-assisted changes with the same tests, linters, and build checks expected for human contributions.
• Never claim that tests, benchmarks, or tools were run unless they were actually run.
• Remove generated boilerplate and unnecessary explanations before submitting a contribution.