Add em/en dash cut, gap-filling tell, and diff-anchored pattern (v2.7.0)

- §14: turn em-dash "overuse" into a hard cut (no em or en dashes in the
  final rewrite), with a replacement ladder and a final scan. Idea from #96.
- §21: expand to cover speculative gap-filling ("maintains a low profile,"
  "keeps personal details private") where a model invents filler instead of
  saying a source is missing. Idea from #111.
- New pattern #30, diff-anchored writing: describe the thing as it is, not as
  a narration of what changed. Idea from #81.

Hand-ported lean versions rather than merging the source PRs. 30 patterns
total; README and AGENTS.md updated to match.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

AGENTS.md

@@ -15,7 +15,7 @@ A **Claude Code / OpenCode skill** implemented entirely as Markdown. The runtime
 
 `SKILL.md` and `README.md` must stay in sync. When you change behavior or content:
 
-- **Patterns:** the skill currently defines **29 numbered patterns**. If you add, remove, or renumber any, update the README pattern table, its "N Patterns Detected" heading, and every cross-reference in the same change. Keep numbering stable unless you are deliberately renumbering.
+- **Patterns:** the skill currently defines **30 numbered patterns**. If you add, remove, or renumber any, update the README pattern table, its "N Patterns Detected" heading, and every cross-reference in the same change. Keep numbering stable unless you are deliberately renumbering.
 - **Version:** `SKILL.md` frontmatter has a `version:` field and `README.md` has a "Version History" section. Bump both together.
 - **Non-obvious fixes:** if you change the prompt to handle a tricky failure mode (a repeated mis-edit, an unexpected tone shift), add a short note to the README version history explaining what was fixed and why.
 

README.md

@@ -88,7 +88,7 @@ The skill also includes a final "obviously AI generated" audit pass and a second
 
 > "LLMs use statistical algorithms to guess what should come next. The result tends toward the most statistically likely result that applies to the widest variety of cases."
 
-## 29 Patterns Detected (with Before/After Examples)
+## 30 Patterns Detected (with Before/After Examples)
 
 ### Content Patterns
 
@@ -117,7 +117,7 @@ The skill also includes a final "obviously AI generated" audit pass and a second
 
 | # | Pattern | Before | After |
 |---|---------|--------|-------|
-| 14 | **Em dash overuse** | "institutions—not the people—yet this continues—" | Prefer commas or periods |
+| 14 | **Em/en dashes** | "institutions—not the people—yet this continues—" | Cut them: periods, commas, colons, or parentheses |
 | 15 | **Boldface overuse** | "**OKRs**, **KPIs**, **BMC**" | "OKRs, KPIs, BMC" |
 | 16 | **Inline-header lists** | "**Performance:** Performance improved" | Convert to prose |
 | 17 | **Title Case Headings** | "Strategic Negotiations And Partnerships" | "Strategic negotiations and partnerships" |
@@ -127,6 +127,7 @@ The skill also includes a final "obviously AI generated" audit pass and a second
 | 27 | **Persuasive authority tropes** | "At its core, what matters is..." | State the point directly |
 | 28 | **Signposting announcements** | "Let's dive in", "Here's what you need to know" | Start with the content |
 | 29 | **Fragmented headers** | "## Performance" + "Speed matters." | Let the heading do the work |
+| 30 | **Diff-anchored writing** | "This function was added to replace..." | Describe what it does, not what changed |
 
 ### Communication Patterns
 
@@ -179,6 +180,7 @@ The skill also includes a final "obviously AI generated" audit pass and a second
 
 ## Version History
 
+- **2.7.0** - Added pattern #30 (diff-anchored writing); made em/en dashes a hard cut rather than "overuse"; expanded #21 to cover speculative gap-filling ("maintains a low profile"). 30 patterns total.
 - **2.6.0** - Cleanup pass: consolidated the duplicated workflow sections, gated the personality guidance to content where voice is wanted, removed the model-fingerprinting subsection, and condensed the worked example. No change to the 29 patterns.
 - **2.5.1** - Added a passive-voice / subjectless-fragment rule, raising the total to 29 patterns
 - **2.5.0** - Added patterns for persuasive framing, signposting, and fragmented headers; expanded negative parallelisms to cover tailing negations; tightened wording around em dash overuse; fixed frontmatter wording to use "filler phrases"

SKILL.md

@@ -1,6 +1,6 @@
 ---
 name: humanizer
-version: 2.6.0
+version: 2.7.0
 description: |
   Remove signs of AI-generated writing from text. Use when editing or reviewing
   text to make it sound more natural and human-written. Based on Wikipedia's
@@ -256,9 +256,9 @@ Avoiding AI patterns is only half the job. Sterile, voiceless writing is just as
 
 ## STYLE PATTERNS
 
-### 14. Em Dash Overuse
+### 14. Em Dashes (and En Dashes): Cut Them
 
-**Problem:** LLMs use em dashes (—) more than humans, mimicking "punchy" sales writing. In practice, most of these can be rewritten more cleanly with commas, periods, or parentheses.
+**Rule:** The final rewrite contains no em dashes (—) or en dashes (–). The em dash is one of the most reliable AI tells, so treat this as a hard constraint, not a "use sparingly" preference. Replace each one, in rough order of preference: a period (start a new sentence), a comma (a tight aside), a colon (introducing an explanation), parentheses (a true aside), or restructure the sentence. Also catch spaced em dashes (` — `) and double hyphens (` -- `) used the same way.
 
 **Before:**
 > The term is primarily promoted by Dutch institutions—not by the people themselves. You don't say "Netherlands, Europe" as an address—yet this mislabeling continues—even in official documents.
@@ -266,14 +266,14 @@ Avoiding AI patterns is only half the job. Sterile, voiceless writing is just as
 **After:**
 > The term is primarily promoted by Dutch institutions, not by the people themselves. You don't say "Netherlands, Europe" as an address, yet this mislabeling continues in official documents.
 
-Also catch spaced em dashes (` — `) and double hyphens (` -- `) used as em dashes. These are the same pattern in different typography.
-
 **Before:**
 > The new policy — announced without warning — affects thousands of workers. The changes -- long overdue according to critics -- will take effect immediately.
 
 **After:**
 > The new policy, announced without warning, affects thousands of workers. The changes, long overdue according to critics, will take effect immediately.
 
+Before returning the final rewrite, scan it for `—` and `–`. Any hit means the draft isn't done.
+
 
 ### 15. Overuse of Boldface
 
@@ -349,18 +349,24 @@ Also catch spaced em dashes (` — `) and double hyphens (` -- `) used as em das
 > The French Revolution began in 1789 when financial crisis and food shortages led to widespread unrest.
 
 
-### 21. Knowledge-Cutoff Disclaimers
+### 21. Knowledge-Cutoff Disclaimers and Speculative Gap-Filling
 
-**Words to watch:** as of [date], Up to my last training update, While specific details are limited/scarce..., based on available information...
+**Words to watch:** as of [date], Up to my last training update, While specific details are limited/scarce..., based on available information, not publicly available, maintains a low profile, keeps personal details private, prefers to stay out of the spotlight, likely [grew up/studied/began], it is believed that
 
-**Problem:** AI disclaimers about incomplete information get left in text.
+**Problem:** Two related tells. (a) Older models leave hard knowledge-cutoff disclaimers in the text. (b) When a model can't find a source, it writes a paragraph *about* not finding one and then invents plausible filler to cover the gap. For a private person the guess almost always lands on the same stock phrases ("maintains a low profile," "keeps personal details private"), none of it sourced. Say what isn't known, or cut the sentence; don't dress a guess up as fact.
 
-**Before:**
+**Before (cutoff disclaimer):**
 > While specific details about the company's founding are not extensively documented in readily available sources, it appears to have been established sometime in the 1990s.
 
 **After:**
 > The company was founded in 1994, according to its registration documents.
 
+**Before (speculative gap-fill):**
+> Information about her early life is not publicly available, suggesting she maintains a low profile and keeps personal details private. She likely grew up in a middle-class household, which shaped her later interest in education reform.
+
+**After:**
+> Her early life is not documented in the available sources. (Or omit the section.)
+
 
 ### 22. Sycophantic/Servile Tone
 
@@ -466,6 +472,17 @@ Also catch spaced em dashes (` — `) and double hyphens (` -- `) used as em das
 > When users hit a slow page, they leave.
 
 
+### 30. Diff-Anchored Writing
+
+**Problem:** Documentation or comments written as if narrating a change rather than describing the thing as it is. Unless the document is inherently version-scoped (changelogs, release notes, migration guides), it should read coherently without knowing what changed in the last commit.
+
+**Before:**
+> This function was added to replace the previous approach of iterating through all items, which caused O(n²) performance.
+
+**After:**
+> This function uses a hash map for O(1) lookups, avoiding the O(n²) cost of naive iteration.
+
+
 ## DETECTION GUIDANCE
 
 ### What NOT to flag (false positives)
@@ -506,7 +523,7 @@ When you see these, lean toward leaving the prose alone — they are evidence of
 1. Read the input carefully and identify every instance of the patterns above.
 2. Write a **draft rewrite**. Check that it reads naturally aloud, varies sentence length, prefers specific details and simple constructions (is/are/has), and keeps the appropriate register.
 3. Ask: **"What makes the below so obviously AI generated?"** Answer briefly with any remaining tells.
-4. Revise into a **final rewrite** that addresses them.
+4. Revise into a **final rewrite** that addresses them and contains no em or en dashes (see §14).
 
 Deliver the draft, the brief "still-AI" bullets, the final rewrite, and (optionally) a short summary of changes.