Readability check

Run a readability audit on a blog post draft or other multi-paragraph prose. Use when the user asks to check readability ("check readability", "readability pass", "is this readable"), or proactively after a substantial draft is complete — as a second pass after the blog-drafting skill's critical read, not during active drafting.

For short strings — page titles, meta descriptions, schema description fields, FAQ answers, profile bios, repo taglines — use the metadata-check skill. Flesch scoring and the nine-category rubric below don't fit a 5–30 word string and will mislead.

Audience calibration

Always assume the reader reads English as a second language. That's the default, not a fallback.

In technical posts, the technical sections can use domain terms the audience expects — but any non-technical paragraph (introduction, context, conclusion, transitions, examples, analogies) must be readable by a non-technical L2 reader. Setup and motivation paragraphs carry the post for readers who don't know the domain yet; they're where you lose people.

What to check

Read the full post, then report on each criterion below. For every issue, quote the specific text, reference its location (section heading or "intro" / "conclusion"), explain the problem, and suggest a concrete fix.

1. Paragraph structure

• Every paragraph must lead with its most important sentence. The opening sentence should make sense standalone — this is the unit AI systems extract for answers.
• One idea per paragraph. Break paragraphs that do two things.
• Visual density matters more than a strict sentence count, but flag paragraphs over ~8 sentences or ~120 words.

2. Opening paragraph

The first paragraph carries disproportionate weight — it's what AI systems quote and what readers use to decide whether to keep reading. Check specifically:

• Does the first sentence state the point of the post, not just set up context?
• Can the first paragraph stand alone as a summary?
• Is there hedging ("in this post I'll try to...") that can be cut?

3. Sentence length

Use tiered thresholds:

• 14–20 words: normal, no action needed.
• 21–30 words: long. Flag if a paragraph has more than one.
• 30+ words: very long. Flag every instance; suggest a split.

Long sentences are especially costly for L2 readers because they have to hold more grammar in working memory. When a long sentence is unavoidable (e.g. a necessary list), check that the sentences around it are short.

4. Passive voice

Flag passive constructions ("X was done by Y", "it is recommended that..."). For each:

• If the actor is clear and active voice reads naturally, rewrite.
• Keep passive when the actor is genuinely unknown, irrelevant, or when the object is the real topic of the sentence.
• Flag stacked passives (two in one paragraph) even if each is individually defensible.

5. Difficult words

Don't rely on syllable count — it mislabels common words as hard ("information") and simple words as easy ("queue"). Instead, flag a word if:

• A non-technical L2 reader probably wouldn't use it in conversation, and
• A more common synonym exists that fits the sentence.

Examples of words to flag when a simpler option works: utilize (use), leverage (use), facilitate (help), commence (start), subsequently (then), ascertain (find out), endeavor (try).

Exceptions:

• Domain terms the audience expects ("structured data", "hydration", "middleware") — don't flag in technical sections.
• In non-technical paragraphs of technical posts, apply the strict L2 rule even to mild jargon.

When a difficult word is genuinely necessary, check that the surrounding sentences are short and simple so the reader has processing room.

6. Filler and hedging

Flag words that add length without meaning: really, just, very, actually, basically, simply, in order to (→ to), at this point in time (→ now), due to the fact that (→ because). Also flag hedges that weaken claims without reason: I think, sort of, kind of, it could be argued that.

7. Transition words

• Paragraphs should connect with transitions: because, therefore, however, for example, first, in other words, as a result, that said.
• Flag sequences of 3+ paragraphs with no transitions.
• Don't over-correct: natural flow counts. Not every paragraph needs an explicit connector.

8. Variation

• Flag words or phrases repeated 3+ times within ~200 words (excluding articles, prepositions, domain terms).
• Flag 3+ consecutive paragraphs that open with the same sentence structure (e.g. all starting "You can...").
• Suggest synonyms or restructuring.

9. Subheadings and heading hierarchy

• In posts over 1000 words, no prose section should run longer than ~300 words without a subheading.
• Subheadings should be descriptive enough to understand standalone — a reader skimming the table of contents should grasp the post's shape.
• Check heading levels are properly nested (no h2 → h4 jumps).
• Sibling headings should be grammatically parallel (all noun phrases, or all questions, or all imperatives — pick one and stick to it within a section).

Scoring

Report two things.

Flesch Reading Ease (computed: 206.835 − 1.015 × (words/sentences) − 84.6 × (syllables/words)). Target bands:

• 70+ — plain English, comfortable for L2 readers. Aim here for non-technical posts and for non-technical paragraphs in technical posts.
• 60–70 — standard. Acceptable for technical posts overall, provided non-technical sections score higher.
• 50–60 — fairly difficult. Flag; suggest specific cuts.
• Below 50 — hard. Needs rework.

Flesch is mechanical and misses paragraph-level issues, but it's an objective anchor. If possible, also report the score for the intro and conclusion separately — those should sit at the top of the target band.

Per-category status — for each of the 9 checks above, assign one of:

• ✓ Pass — no meaningful issues.
• ⚠ Needs work — a few fixable issues; listed below.
• ✗ Problem — systemic issue across the post.

Output format

## Readability audit: [post title]

### Score
- Flesch Reading Ease: [n] ([band])
- Intro: [n] · Conclusion: [n]
- Per-category: 1. ✓  2. ⚠  3. ✓  4. ✗  5. ⚠  6. ✓  7. ✓  8. ⚠  9. ✓

### Summary
[One paragraph: overall readability, the one or two biggest issues, and which audience the post currently serves vs. which it should serve.]

### Issues found
[Grouped by category. For each: location, quoted text, why it's a problem, concrete fix.]

### What's working
[Specific sentences, paragraphs, or transitions that read well — quote them. Vague praise ("the intro is fine") doesn't help the writer calibrate; specific praise ("the analogy in the 'Setup' section lands because it bridges to a non-technical reader") does.]