Lint the rules you give AI coding agents.

Paste a CLAUDE.md, AGENTS.md, Cursor rule, Copilot instructions, GEMINI.md, or .windsurfrules. Get line-level findings and a score for the instructions your agent reads before it writes code.

Lint a file Open the sample 

Lint result: CLAUDE.md
CLAUDE.md:5   info    R001  Rationale prose: "because"
CLAUDE.md:6   warning R002  Vague wording: "handle", "properly"
CLAUDE.md:10  error   R003  Contradicts line 4: "run the formatter before commit" is both required and forbidden.
CLAUDE.md:11  info    R001  Rationale prose: "so that"
CLAUDE.md:12  warning R002  Vague wording: "ensure"
CLAUDE.md:13  warning R005  Duplicate of line 9.
6 findings, Aibysitter lint score 76/100 (C)
Output from the embedded sample, linted by the same engine as the lint page.

What it checks

Rules files, available now

  • R001 Instructions explain why instead of stating what.
  • R002 Pattern-based: instructions use verbs with no checkable outcome.
  • R003 Mirrored instructions: the same instruction is both required and forbidden.
  • R004 The file is longer than 200 lines.
  • R005 The same instruction appears more than once.
  • R007 A hedge makes the instruction optional.
  • R008 Emphasis is on so many lines that none of it stands out.
  • R009 The file contains a credential.
  • R010 The file assigns the agent a persona instead of stating facts.
  • R011 A heading has no content.
  • R012 A code fence is opened and never closed.
  • R013 Instructions are written as a long paragraph.
  • R014 A line refers to something elsewhere without naming it.
  • R015 A Cursor rule's frontmatter is missing, has unknown keys, or has an invalid alwaysApply.
  • R016 A Cursor rule is in Apply Manually mode and is included only when @-mentioned.

Pull requests, GitHub App

  • P001 Placeholder identifiers
  • P002 TODO stubs
  • P004 Out-of-scope files
  • P005 Secrets in diff
  • P006 Skipped tests
  • P007 Suppressed diagnostics
  • P008 Deleted tests
  • P009 Swallowed exceptions
  • P010 New dependencies
  • P011 CI config edited
  • P013 Committed artifacts
  • P014 Rules file lint
  • P015 Unpinned actions
  • P016 Security exemptions
  • P018 Browser policy loosened
  • P019 Unfinished config values
  • R006 A rules file names a path, script, or target that does not exist in the repository. App-only

Pull request checks run through the Aibysitter GitHub App.

Example rules files

Public-domain rules files for common stacks and agents, each scored by the linter.

Browse the gallery

How the Aibysitter lint score works

Every file starts at 100. Each finding costs points by severity: Error 10, Warning 4, Info 1. One rule costs at most 30. Total costs per severity are capped: Error 40, Warning 30, Info 10. The lowest possible score is 20. Grades: A ≥ 90, B ≥ 80, C ≥ 70, D ≥ 60, F below 60.

Code blocks are ignored.

Read the rules