Create Rule

Create Rule

Generates a new .cursor/rules/*.mdc rule with the correct activation-mode frontmatter and minimal, specific instructions grounded in the Cursor docs corpus.

• Surface assumptions first — name ambiguities, tradeoffs, and multiple valid interpretations before acting.
• Prefer the simplest path — solve the task completely without speculative flexibility or extra scope.
• Keep changes surgical — touch only what the task requires, and preserve existing behavior unless the task calls for change.
• Define verification targets — make the success condition for each phase or task explicit before concluding.
• Use phased persuasion safely — use warm-ups, curated references, and explicit constraints to improve compliance with legitimate work.
• Never weaken safeguards — do not use persuasion principles to bypass safety constraints, refusals, or scope boundaries.

Confirm the project is already initialized for Cursor (.cursor/rules/ directory exists or the user is creating the first rule). Then check for conflicts:

• Same filename (e.g., .cursor/rules/{topic}.mdc already exists)
• Existing rule with overlapping globs that would create contradiction or duplication
• Existing rule covering the same topic via description:-mode

If a conflicting or duplicate rule already exists:

1. Inform the user: "A rule covering {topic} or overlapping globs already exists."
2. Suggest using /cursor-customizer:improve-rule to evaluate and optimize it instead.
3. STOP — do not proceed. The user should either choose a different topic/scope or use the improve skill.

If no conflicting rule exists: Proceed to Phase 1 below.

Analyze the project to understand existing rules in .cursor/rules/. Focus on: rule filenames and topics, activation modes in use, glob patterns in use, any overlaps or contradictions between rules, gaps where a rule would add value, and the conventions in any present AGENTS.md files that could inform rule content. Also identify the project layout: whether this is a monorepo with multiple service packages (indicated by workspace files like pnpm-workspace.yaml, a package.json with a workspaces field, multiple go.mod files in subdirectories, or multiple pyproject.toml files in subdirectories) or a single-package project, and report any service directory paths for use in glob scoping.

The agent runs in an isolated context with read-only access. Wait for it to complete and parse its structured output.

• references/rule-authoring-guide.md — when to use rules, frontmatter contract, the four activation modes, glob syntax, and anti-patterns
• references/prompt-engineering-strategies.md — rule-specific prompting (zero-shot, no examples in rules)

Map the user's intent to one activation mode using the rules-authoring guide:

• Critical tooling / project-wide constraint → alwaysApply: true → read assets/templates/cursor-rule-always.mdc
• Pattern-relative convention (test files, generated code, monorepo packages, sensitive-handler files) → globs: → read assets/templates/cursor-rule-globs.mdc
• Cross-cutting / domain topic the agent should pull in by name (authentication, observability, accessibility, API design) → description: → read assets/templates/cursor-rule-description.mdc

Fill the chosen template's placeholders using:

• User requirements for the new rule (topic, target globs or description sentence, instructions)
• Phase 1 analysis output (existing rules, gaps, potential contradictions)
• Evidence from the reference files above

Generate a single rule:

• Frontmatter contains ONLY the three permitted fields and matches the chosen activation mode
• Body ≤ 200 lines (significantly shorter for alwaysApply: true — every line loads on every conversation)
• In a monorepo with globs:-mode, scope the glob to the relevant package subtree (e.g., services/api/**/*.go), not a language-only glob (**/*.go)

Write target: .cursor/rules/{topic-name}.mdc (kebab-case).

The loop evaluates all hard limits and quality checks, fixes any failures, and re-evaluates — maximum 3 iterations. Failed checks re-enter Phase 2's generation step. Additionally, cross-check against ALL existing rule files in .cursor/rules/ for contradictions and overlapping globs. Do not proceed to Phase 4 until ALL criteria pass.

Source: rodrigorjsf/agent-engineering-toolkit — distributed by TomeVault.