MCP tool results used Markdown ATX headings (##/###/####) for section
headers — the status summary, each search hit, every file section in an
exploration — which Markdown-rendering clients (e.g. the Claude Code
VSCode extension) blow up to H1–H4 font size, filling the transcript with
oversized lines (worst on search/explore, where the noise scales with
result count). Swap them all for bold labels, which render at body size
while keeping the same structure. CLI/TTY output (ContextBuilder) is
unchanged — the issue notes it's fine.
The format is parse-coupled, so kept in sync:
- The explore truncation boundary and the offload chunker
(reasoning/reasoner.ts) both key off the per-file header, now a unique
`**`-prefixed marker emitted via a shared fileSectionHeader() helper.
- Updated the offload strip regexes and switched the opt-in report-style
prompt off ATX headings (same client, same rendering issue).
- Updated test helpers (sectionFor, sourcedFiles, the callers
section-boundary scan) that scanned the old markers.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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