Built-in tool: evaluates an arithmetic expression (+ - * / % ^ and parentheses) without eval.
eval
Ask the user before running (rendered as a Confirmation).
Who provides the tool when it is not the agent itself (e.g. an MCP server), shown next to the title.
Human-readable label for the UI (e.g. an MCP tool's title); null shows name.
What one call does (ACP ToolKind vocabulary), which picks its step view; none by default.
ToolKind
Run the tool. Throwing reports a tool error back to the model.
What one call means for the UI (a delegation, a skill load…); an ordinary function by default.
The file path or URL one call acts on (ACP ToolCallLocation); none by default.
ToolCallLocation
Label for one call from its arguments (e.g. the skill or agent it names); defaults to title.