Docstring

Target file: $1 Symbol (optional, may be empty): $2

Steps:

1. Read the file at path $1.
2. Detect the file's language from its extension/syntax and identify that language's standard doc-comment convention (e.g. Python triple-quoted docstrings, JSDoc /** */ for JS/TS, Rustdoc ///, Godoc comments above the declaration, Javadoc, XML doc comments for C#, etc.).
3. If $2 is non-empty: find only the function/method/class named $2 in the file. If it already has a doc comment, leave it. If missing, add one. Do not touch any other symbol.
4. If $2 is empty: scan the whole file for functions, methods, and classes that have no doc comment (skip ones that already have one). Add one to each.
5. For each doc comment you add, base it strictly on what the code actually does — read the function body, parameter usage, and return statement(s). Do not guess intent beyond what the code shows. Include: a one- to two-sentence summary, each parameter (name + purpose inferred from usage), and the return value if any, using the target language's normal doc-comment tags/format (e.g. Args/Returns for Python, @param/@returns for JSDoc, etc.).
6. Only insert/edit comment text. Never change code logic, formatting of code lines, imports, or function signatures.
7. Use Grep first if the file is large, to locate function/class definitions efficiently, then Edit to insert each doc comment.
8. When done, report a short bullet list: which symbols got a new doc comment (with line numbers), and which were already documented and skipped.