Struct ToolDefinition 

pub struct ToolDefinition {
    pub name: String,
    pub description: String,
    pub input_schema: ToolInputSchema,
    pub annotations: Option<ToolAnnotations>,
    pub should_defer: Option<bool>,
    pub always_load: Option<bool>,
    pub is_mcp: Option<bool>,
    pub search_hint: Option<String>,
    pub aliases: Option<Vec<String>>,
    pub user_facing_name: Option<String>,
    pub interrupt_behavior: Option<String>,
}

Fields

name: String

description: String

input_schema: ToolInputSchema

annotations: Option<ToolAnnotations>

Optional annotations for tool classification

should_defer: Option<bool>

When true, this tool is deferred (requires ToolSearch to load)

always_load: Option<bool>

When true, this tool is never deferred (full schema always sent)

is_mcp: Option<bool>

When true, this is an MCP tool

search_hint: Option<String>

Short capability phrase for keyword search (3-10 words)

aliases: Option<Vec<String>>

Optional aliases for backwards compatibility when a tool is renamed

user_facing_name: Option<String>

Human-readable name for display in the UI (e.g., “Update” vs “Edit”)

interrupt_behavior: Option<String>

Interrupt behavior: ‘cancel’ (stop on user interrupt) or ‘block’ (wait for completion)

Implementations

impl ToolDefinition

pub fn new(name: &str, description: &str, input_schema: ToolInputSchema) -> Self

Create a new tool definition (annotations defaults to None)

pub fn with_deferred(self, should_defer: bool) -> Self

Build with deferred loading support

pub fn with_always_load(self) -> Self

Mark as always loaded (never deferred)

pub fn with_mcp(self) -> Self

Mark as MCP tool

pub fn with_search_hint(self, hint: &str) -> Self

Set search hint for keyword search

pub fn interrupt_behavior(&self) -> InterruptBehavior

Get interrupt behavior: ‘cancel’ (stop on user interrupt) or ‘block’ (wait for completion) Default: ‘block’

pub fn backfill_observable_input(&self, _input: &mut Value)

Backfill observable input before observers see it (hooks, events, transcript). Mutates in place to add legacy/derived fields. Must be idempotent. Default: no-op. Override via with_interrupt_behavior for tools that need it.

pub fn is_concurrency_safe(&self, _input: &Value) -> bool

Check if tool can run concurrently (default: false)

pub fn is_read_only(&self, _input: &Value) -> bool

Check if tool only reads data (default: false)

pub fn is_destructive(&self, input: &Value) -> bool

Check if tool performs destructive operations (default: false)

pub fn is_idempotent(&self) -> bool

Check if tool is idempotent (can be run multiple times safely)

pub fn get_use_summary(&self, input: &Value) -> String

Get tool use summary for compact views

Trait Implementations

impl Clone for ToolDefinition

fn clone(&self) -> ToolDefinition

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ToolDefinition

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

Formats the value using the given formatter.

impl Default for ToolDefinition

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ToolDefinition

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for ToolDefinition

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

where __S: Serializer,

Serialize this value into the given Serde serializer.