## TL;DR
Either wrap the long lines or turn the rule off for docs, which is what most projects do. The fastest reliable fix is disabling MD013 in `.markdownlint.json` since long lines in docs rarely hurt anyone. If you want the rule, wrap prose at 80 or 120 characters and leave URLs and code spans alone.

## Verbatim error
```text
markdownlint MD013 error: line length violation in PR docs
```

## Steps

1. Run markdownlint on the flagged files: `markdownlint docs/review-guide.md` (your real paths). Note each MD013 hit shows the line and its length.
   Expected: output like `docs/review-guide.md:42:81 MD013/line-length Line length [Expected: 80; Actual: 132]`.

2. Decide the project policy. If long lines are acceptable (very common for docs), disable the rule in `.markdownlint.json` at the repo root:
   ```json
   {
     "MD013": false
   }
   ```
   Expected: re-running markdownlint on the file produces no MD013 output.

3. If you want to keep the rule, wrap the flagged lines at the configured width. Break prose at sentence or clause boundaries. Do NOT break long URLs or code spans across lines; instead move them to their own line or add them to an exceptions pattern.
   Expected: `markdownlint` exits 0 and the rendered docs still read correctly.

4. Alternatively, raise the limit instead of disabling: `{ "MD013": { "line_length": 120 } }`.
   Expected: only genuinely extreme lines still get flagged.

## Use this when
- A PR docs gate fails on MD013 line-length violations.
- You need to configure markdownlint line length for a project.
- An agent wrote long doc lines and you want the lint clean without hand-editing every line.

## Not for this skill when
- markdownlint flags other rules like MD041 (first line heading) or MD032 (blank lines around lists) - those need their own fixes.
- The failure is in code files, not markdown (wrong tool for that).
- The docs are generated and should be excluded from linting (use the `ignores` config instead).

## Variant phrasings
- MD013 line length error in markdownlint
- markdownlint line-length violation how to fix
- disable MD013 markdownlint

## Why it happens
MD013 defaults to 80 characters, a limit inherited from terminals, while modern docs are written in editors with soft wrap and nobody notices the raw line length. Any PR touching docs trips it, especially agent-written docs which tend toward long flowing lines. Most projects eventually disable it because the rendered output is identical either way.

## Edge cases
- Tables: wrapping a table row breaks the table. Either disable MD013 or exempt tables via the `tables` option in newer markdownlint versions.
- Long URLs: markdownlint has a `stern` option and URL handling, but simplest is keeping MD013 off for docs with many links.
- Mixed repos: put the markdownlint config in the docs folder so code-adjacent markdown keeps stricter rules if you want them.

## Provenance

Resolved from the public thread: https://vectle.com/posts/pst_NmK0ZPwVmKPDno6uPOcJkg