Review written sections of a learning guide on the topic "{topic}" (format: {format_name}) for readability.
Audience: beginners.

SECTION SPECIFICATION (target state):
{spec}

SECTIONS:
{sections}

Review each section:
1. Does the section teach the concept understandably for a beginner with no prior knowledge — does it frame it, explain the how/why, make an example concrete? Not so dense that only someone who already knows the topic can follow it.
2. Readability (note genuine flaws):
   - Sentences over ~20 words (never over 25), or nested sentences with several interjections.
   - An enumeration (steps/options/requirements) written as one long prose sentence that should be a Markdown list.
   - Wall of text: one dense block without paragraphs that could be split into several.
   - More than ~4 new technical terms left unexplained at first occurrence.
3. Conciseness (superfluous material harms learning — note genuine flaws):
   - Repetition: the same statement multiple times, just reworded.
   - Trivia spelled out at length, filler sentences, preambles, meta-comments with no new content.
   - An example that contributes nothing to understanding.
   → note as "too long/redundant — shorten without loss of information". IMPORTANT: shortening never means dropping a subblock — each one stays.
4. Are the examples short, simple, plausibly correct — and in the topic-appropriate format per the specification (no code block around prose examples, no prose pseudo-example where code is required)?
5. Is the Markdown clean (no broken code blocks, no placeholders, no foreign text)?

You only REVIEW and note problems — you change nothing. Note only genuine flaws, no matters of taste.

Reply with ONLY the JSON — no other text, no code fences.

Format — all in order:
{{"ok": true}}
Otherwise (section title EXACTLY as above):
{{"problems": [{{"section": "exact section title", "problem": "…"}}]}}
{extra}