Struct CallToolResult 

pub struct CallToolResult {
    pub content: Vec<Annotated<RawContent>>,
    pub structured_content: Option<Value>,
    pub is_error: Option<bool>,
    pub meta: Option<Meta>,
}

The result of a tool call operation.

Contains the content returned by the tool execution and an optional flag indicating whether the operation resulted in an error.

Fields

content: Vec<Annotated<RawContent>>

The content returned by the tool (text, images, etc.)

structured_content: Option<Value>

An optional JSON object that represents the structured result of the tool call

is_error: Option<bool>

Whether this result represents an error condition

meta: Option<Meta>

Optional protocol-level metadata for this result

Implementations

impl CallToolResult

pub fn success(content: Vec<Annotated<RawContent>>) -> CallToolResult

Create a successful tool result with unstructured content

pub fn error(content: Vec<Annotated<RawContent>>) -> CallToolResult

Create an error tool result with unstructured content

pub fn structured(value: Value) -> CallToolResult

Create a successful tool result with structured content

Example

use rmcp::model::CallToolResult;
use serde_json::json;

let result = CallToolResult::structured(json!({
    "temperature": 22.5,
    "humidity": 65,
    "description": "Partly cloudy"
}));

pub fn structured_error(value: Value) -> CallToolResult

Create an error tool result with structured content

Example

use rmcp::model::CallToolResult;
use serde_json::json;

let result = CallToolResult::structured_error(json!({
    "error_code": "INVALID_INPUT",
    "message": "Temperature value out of range",
    "details": {
        "min": -50,
        "max": 50,
        "provided": 100
    }
}));

pub fn into_typed<T>(self) -> Result<T, Error>

where T: DeserializeOwned,

Convert the structured_content part of response into a certain type.

About json schema validation

Since rust is a strong type language, we don’t need to do json schema validation here.

But if you do have to validate the response data, you can use jsonschema crate.

Trait Implementations

impl CallToolResultExt for CallToolResult

fn get_mcp_metadata(&self) -> Result<McpToolResultMetadata>

Extract strongly-typed MCP execution metadata from _meta field Returns error if metadata is missing or invalid

impl Clone for CallToolResult

fn clone(&self) -> CallToolResult

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CallToolResult

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for CallToolResult

fn deserialize<D>( deserializer: D, ) -> Result<CallToolResult, <D as Deserializer<'de>>::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for CallToolResult

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for CallToolResult

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 CallToolResult