tools: claude: improve instructions for posting comments

[pzmarzly]

In https://github.com/facebook/bpfilter/actions/runs/22465679917 there were 2 issues:

1. A subagent posted its finding as a comment, leading to a duplicate comment in Restore counter values on chain update #416 (thanks @yaakov-stein for reporting).
2. Claude had problems figuring out the jq | gh invocation, leading to many failed Tool calls (eventually succeeding though).

Demo: https://github.com/pzmarzly/demo--claude-bot-reviews/actions/runs/22489697229?pr=8#:~:text=input%2C%200%20output-,%F0%9F%94%A7%20Write,-Parameters%3A

[github-actions]

Claude: review of facebook/bpfilter #445 (a056581)

No issues found. The changes are correct and well-structured:

• The new subagent restriction paragraph clearly prevents duplicate comments by explicitly forbidding subagents from calling gh or mcp__github_inline_comment__create_inline_comment.
• The printf '%s' "$BODY" > pr-review-body.txt + gh api -F body=@pr-review-body.txt approach is more robust than the previous jq | gh api --input - pattern and correctly handles markdown special characters.
• YAML indentation is consistent with the surrounding context.
• Commit message follows project conventions (tools: claude: component/subcomponent, imperative mood, under 72 chars).

[qdeslandes]

Good for me, thanks!

[qdeslandes]

I think I requested changes with the previous review, mistake on my end! Approving :)