@definitelytyped/dtslint is a command-line tool that lints TypeScript declaration files (.d.ts) within the DefinitelyTyped repository. It enforces style conventions and detects common errors specific to type definitions, ensuring consistency and quality across the extensive collection of community-contributed type definitions. This package helps maintainers and contributors adhere to best practices, leading to more reliable and accurate type information for JavaScript libraries. It's crucial for validating changes before submitting pull requests to DefinitelyTyped.