Struct Tool

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

Definition for a tool the client can call.

JSON schema

{
 "description": "Definition for a tool the client can call.",
 "type": "object",
 "required": [
   "inputSchema",
   "name"
 ],
 "properties": {
   "_meta": {
     "description": "See [specification/2025-06-18/basic/index#general-fields] for notes on _meta usage.",
     "type": "object",
     "additionalProperties": {}
   },
   "annotations": {
     "description": "Optional additional tool information.\n\nDisplay name precedence order is: title, annotations.title, then name.",
     "$ref": "#/definitions/ToolAnnotations"
   },
   "description": {
     "description": "A human-readable description of the tool.\n\nThis 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.",
     "type": "string"
   },
   "inputSchema": {
     "description": "A JSON Schema object defining the expected parameters for the tool.",
     "type": "object",
     "required": [
       "type"
     ],
     "properties": {
       "properties": {
         "type": "object",
         "additionalProperties": {
           "type": "object",
           "additionalProperties": true
         }
       },
       "required": {
         "type": "array",
         "items": {
           "type": "string"
         }
       },
       "type": {
         "type": "string",
         "const": "object"
       }
     }
   },
   "name": {
     "description": "Intended for programmatic or logical use, but used as a display name in past specs or fallback (if title isn't present).",
     "type": "string"
   },
   "outputSchema": {
     "description": "An optional JSON Schema object defining the structure of the tool's output returned in\nthe structuredContent field of a CallToolResult.",
     "type": "object",
     "required": [
       "type"
     ],
     "properties": {
       "properties": {
         "type": "object",
         "additionalProperties": {
           "type": "object",
           "additionalProperties": true
         }
       },
       "required": {
         "type": "array",
         "items": {
           "type": "string"
         }
       },
       "type": {
         "type": "string",
         "const": "object"
       }
     }
   },
   "title": {
     "description": "Intended for UI and end-user contexts — optimized to be human-readable and easily understood,\neven by those unfamiliar with domain-specific terminology.\n\nIf not provided, the name should be used for display (except for Tool,\nwhere annotations.title should be given precedence over using name,\nif present).",
     "type": "string"
   }
 }
}

Fields

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.

input_schema: ToolInputSchema

meta: Option<Map<String, Value>>

See [specification/2025-06-18/basic/index#general-fields] for notes on _meta usage.

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>

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).

Trait Implementations

impl Clone for Tool

fn clone(&self) -> Tool

Returns a duplicate of the value.

const 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 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.