How do I choose a Cursor rule attachment mode?

alwaysApply: true always includes the rule and ignores globs and description. With false, globs auto-attach for matching files; description without globs lets Agent choose when relevant; neither means @-mention only.

Do project rules affect Cursor Tab?

No. Rules do not affect Cursor Tab. Keep rules under 500 lines.

Fix

Cursor .mdc rule frontmatter mistakes

Answer

Cursor project rules need a .mdc file in .cursor/rules with description, globs, and alwaysApply frontmatter. A plain .md file there is ignored. Choose the fields for the intended attachment mode.

Scope Tool-agnostic. Written against Cursor project rules (.mdc), Claude Code CLAUDE.md, AGENTS.md, and GitHub Copilot repository instructions as documented on 2026-10-15.

Last verified 2026-10-15

The Vibe Coder Starter pack ships a Cursor .mdc rule alongside its other formats. Its pinned scope is: Tool-agnostic. Written against Cursor project rules (.mdc), Claude Code CLAUDE.md, AGENTS.md, and GitHub Copilot repository instructions as documented on 2026-10-15. Project rules live in .cursor/rules and must use the .mdc extension. A plain .md file in that directory is ignored. Frontmatter fields are description, globs, and alwaysApply.

With alwaysApply: true, the rule is always included; globs and description are ignored. With alwaysApply: false plus globs, the rule is auto-attached when a matching file is in context. Separate multiple glob patterns with commas. A glob needs to match the files you want the rule to cover.

With alwaysApply: false and a description but no globs, Agent pulls the rule in when relevant based on that description. This is Apply Intelligently. With alwaysApply: false and neither description nor globs, the rule is included only when you @-mention it. If Apply Intelligently never applies, make sure a description is set; for specific files, make sure the glob matches.

Loadout ships this frontmatter in its .mdc files. The vibe-coder-starter rule sets alwaysApply: true and globs: "**/*"; the glob is ignored in that mode. The Unity game pack sets globs: "**/*.cs" with alwaysApply: false, while Godot uses globs: "**/*.gd" with alwaysApply: false. Those game rules attach when a matching file is in context.

Keep rules under 500 lines. Rules do not affect Cursor Tab. Check the file extension, the frontmatter fields, and the attachment mode when a project rule never applies.

Last verified 2026-10-15. doc-verified.

Vibe Coder Starter pack — Safe defaults for any AI coding agent, in any stack.

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Questions

Why is my Cursor project rule ignored?: Cursor project rules need a .mdc file in .cursor/rules with description, globs, and alwaysApply frontmatter. A plain .md file there is ignored. Choose the fields for the intended attachment mode.
How do I choose a Cursor rule attachment mode?: alwaysApply: true always includes the rule and ignores globs and description. With false, globs auto-attach for matching files; description without globs lets Agent choose when relevant; neither means @-mention only.
Do project rules affect Cursor Tab?: No. Rules do not affect Cursor Tab. Keep rules under 500 lines.
When was this Cursor frontmatter rule last checked?: Last verified 2026-10-15. doc-verified.