Find undocumented functions first. "Which exported functions in src/api/ are missing JSDoc comments?" Claude uses Grep to check for @param and @returns patterns across the files.
Then generate in batches. "Add JSDoc to every exported function in auth.js." Claude reads the function signatures, infers parameter types from usage, and writes the comments. I want to flag one thing: review the output before applying. Claude sometimes infers wrong types for overloaded functions or gets the return type wrong when a function has multiple return paths. The faster you catch a bad doc comment, the less technical debt you carry.