Enum Tool 

pub enum Tool {
    Command {
        command: String,
        args: Option<String>,
    },
    Read {
        file_path: String,
        offset: Option<u64>,
        limit: Option<u64>,
    },
    Write {
        file_path: String,
        content: String,
    },
    Edit {
        file_path: String,
        old_string: String,
        new_string: String,
        replace_all: bool,
    },
    MultiEdit {
        file_path: String,
        edits: Vec<EditOp>,
    },
    Bash {
        command: String,
        workdir: Option<String>,
        timeout_ms: Option<u64>,
        description: Option<String>,
        run_in_background: bool,
    },
    Raw {
        tool_name: String,
        input: Value,
    },
}

A canonical tool invocation.

Known tools are normalized to Claude-canonical names with typed arguments. Everything else — MCP tools (mcp__*), harness-private tools, anything unmodeled — lands in Tool::Raw with its name and untouched input.

Variants

Command

A command the user ran at the harness itself — a slash command, not a model tool call. It rides on a Role::User turn, and whatever the harness printed back arrives as the paired Block::ToolResult.

The leading / in name is what distinguishes it canonically: no model-facing tool name may start with one, so every codec and renderer round-trips it through Tool::from_canonical without a special case. (command rather than name: the enum is tagged by name, so a field of that name would collide with the tag on the wire.)

Fields

command: String

Canonical name including the leading slash, e.g. "/release".

args: Option<String>

Everything the user typed after the command name, when any.

Read

Fields

file_path: String

offset: Option<u64>

limit: Option<u64>

Write

Fields

file_path: String

content: String

Edit

Fields

file_path: String

old_string: String

new_string: String

replace_all: bool

MultiEdit

Fields

file_path: String

edits: Vec<EditOp>

Bash

Fields

command: String

workdir: Option<String>

timeout_ms: Option<u64>

description: Option<String>

run_in_background: bool

Raw

MCP tools, harness-private tools, and anything whose input doesn’t fit a typed variant. Holds the canonical name and the untouched input; always lossless.

Fields

tool_name: String

input: Value

Implementations

impl Tool

pub fn from_canonical(name: &str, input: Value) -> Tool

Build a Tool from a canonical tool name and input — names and argument keys already in the Claude convention (Read/Edit/Bash, file_path/old_string/…).

A typed variant is used only when the input fits its schema exactly; any unexpected key falls through to Tool::Raw. The mapping is lossless.

pub fn to_canonical(&self) -> (String, Value)

Inverse of Tool::from_canonical: the canonical name and input for this tool, ready for a codec to denormalize into a harness’s native names and keys.

Trait Implementations

impl Clone for Tool

fn clone(&self) -> Tool

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Tool

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Tool

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for Tool

fn eq(&self, other: &Tool) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for Tool

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Tool