Struct Tool 

pub struct Tool {
    pub meta: Option<Map<String, Value>>,
    pub annotations: Option<ToolAnnotations>,
    pub description: Option<String>,
    pub icons: Option<Vec<Icon>>,
    pub input_schema: ToolInputSchema,
    pub name: String,
    pub output_schema: Option<ToolOutputSchema>,
    pub title: Option<String>,
}

Definition for a tool the client can call.

Fields

meta: Option<Map<String, Value>>

annotations: Option<ToolAnnotations>

Optional additional tool information.

Display name precedence order is: title, annotations.title, then name.

description: Option<String>

A human-readable description of the tool.

This can be used by clients to improve the LLM’s understanding of available tools. It can be thought of like a “hint” to the model.

icons: Option<Vec<Icon>>

Optional set of sized icons that the client can display in a user interface.

Clients that support rendering icons MUST support at least the following MIME types:

• image/png - PNG images (safe, universal compatibility)
• image/jpeg (and image/jpg) - JPEG images (safe, universal compatibility)

Clients that support rendering icons SHOULD also support:

• image/svg+xml - SVG images (scalable but requires security precautions)
• image/webp - WebP images (modern, efficient format)

input_schema: ToolInputSchema

A JSON Schema object defining the expected parameters for the tool.

Tool arguments are always JSON objects, so type: "object" is required at the root. Beyond that, any JSON Schema 2020-12 keyword may appear alongside type — including composition keywords (oneOf, anyOf, allOf, not), conditional keywords (if/then/else), reference keywords ($ref, $defs, $anchor), and any other standard validation or annotation keywords.

Property schemas may carry an x-mcp-header annotation to mirror the argument value into an HTTP header on the Streamable HTTP transport. See the Streamable HTTP transport specification for the validity and extraction rules.

Defaults to JSON Schema 2020-12 when no explicit $schema is provided.

name: String

Intended for programmatic or logical use, but used as a display name in past specs or fallback (if title isn’t present).

output_schema: Option<ToolOutputSchema>

An optional JSON Schema object defining the structure of the tool’s output returned in the structuredContent field of a CallToolResult. This can be any valid JSON Schema 2020-12.

Defaults to JSON Schema 2020-12 when no explicit $schema is provided.

title: Option<String>

Intended for UI and end-user contexts — optimized to be human-readable and easily understood, even by those unfamiliar with domain-specific terminology.

If not provided, the name should be used for display (except for Tool, where annotations.title should be given precedence over using name, if present).

Implementations

impl Tool

pub fn new(input_schema: ToolInputSchema, name: String) -> Tool

Creates a value from its required fields; optional fields are None.

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<(), Error>

Formats the value using the given formatter.

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

fn deserialize<__D>( __deserializer: __D, ) -> Result<Tool, <__D as Deserializer<'de>>::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 as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Tool