Struct NoParams 

pub struct NoParams;

A marker type for tools that take no parameters.

Use this instead of () when defining tools with no input parameters. The unit type () generates "type": "null" in JSON Schema, which many MCP clients reject. NoParams generates "type": "object" with no required properties, which is the correct schema for parameterless tools.

Example

use tower_mcp::{ToolBuilder, CallToolResult, NoParams};

let tool = ToolBuilder::new("get_status")
    .description("Get current status")
    .handler(|_input: NoParams| async move {
        Ok(CallToolResult::text("OK"))
    })
    .build()
    .unwrap();

Trait Implementations

impl Clone for NoParams

fn clone(&self) -> NoParams

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for NoParams

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

Formats the value using the given formatter.

impl Default for NoParams

fn default() -> NoParams

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for NoParams

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl JsonSchema for NoParams

fn schema_name() -> Cow<'static, str>

The name of the generated JSON Schema.

fn json_schema(_generator: &mut SchemaGenerator) -> Schema

Generates a JSON Schema for this type.

fn inline_schema() -> bool

Whether JSON Schemas generated for this type should be included directly in parent schemas, rather than being re-used where possible using the $ref keyword.

fn schema_id() -> Cow<'static, str>

Returns a string that uniquely identifies the schema produced by this type.

impl PartialEq for NoParams

fn eq(&self, other: &NoParams) -> 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 Copy for NoParams

impl Eq for NoParams

impl StructuralPartialEq for NoParams