# [[.Title]]: plan

## What it does

Counts the lines in a text file the user chooses, and saves a short summary
next to it.

## Chat tools

- `[[.Short]]_count_lines`: reads a file and returns its line count. Read-only.
- `[[.Short]]_save_summary`: writes `<file>.summary.txt` next to the file.
  Mutating; checks `host.files.can_write` first.

## Permissions

- `files`: to read the file the user chose and write the summary beside it.

## Dependencies

- `[[.SDKModule]]`: the Cletus plugin SDK.

## Notes for review

- Direct file access: `internal/tools` reads and writes only paths returned
  by `host.files.resolve`, after `host.files.can_write` for writes.