<tool name="patch_dataset_split">
  <description>Edit an existing split of the dataset the user is viewing — its name, description, and/or color — identified by its current name. Only the fields you pass are changed. Pass description: null to clear the description; name and color cannot be cleared, only replaced with a new non-empty value. Does not change which rows are in the split.</description>
  <when_to_use>
    - The user asks to rename a split, change its description, or recolor it.
  </when_to_use>
  <preflight>
    - Get the split's current name from list_splits (splits are global, so any existing split can be edited by name). Split names are unique instance-wide; a duplicate new name fails.
  </preflight>
  <rules>
    - Propose the edit by calling this tool directly. In manual approval mode the browser renders an inline accept/reject card and applies it only when the user accepts; in bypass mode it is applied immediately. The card is the approval surface — do not ask a separate yes/no question (or call ask_user) to confirm before calling it.
    - To change which rows are in a split, use set_dataset_example_splits.
  </rules>
</tool>
