Struct DiscoverResult 

pub struct DiscoverResult {
    pub cache_scope: DiscoverResultCacheScope,
    pub capabilities: ServerCapabilities,
    pub instructions: Option<String>,
    pub meta: Option<ResultMetaObject>,
    pub result_type: String,
    pub supported_versions: Vec<String>,
    pub ttl_ms: u64,
}

Latest MCP Protocol 2026_07_28 The result returned by the server for a {@link DiscoverRequestserver/discover} request.

JSON schema

{
 "description": "The result returned by the server for a {@link DiscoverRequestserver/discover} request.",
 "type": "object",
 "required": [
   "cacheScope",
   "capabilities",
   "resultType",
   "supportedVersions",
   "ttlMs"
 ],
 "properties": {
   "_meta": {
     "$ref": "#/$defs/ResultMetaObject"
   },
   "cacheScope": {
     "description": "Indicates the intended scope of the cached response, analogous to HTTP\nCache-Control: public vs Cache-Control: private.\n\n- \"public\": The response does not contain user-specific data. Any\n  client or intermediary (e.g., shared gateway, caching proxy) MAY cache\n  the response and serve it across authorization contexts.\n- \"private\": The response MAY be cached and reused only within the\n  same authorization context. Caches MUST NOT be shared across\n  authorization contexts (e.g., a different access token requires a\n  different cache).",
     "type": "string",
     "enum": [
       "private",
       "public"
     ]
   },
   "capabilities": {
     "description": "The capabilities of the server.",
     "$ref": "#/$defs/ServerCapabilities"
   },
   "instructions": {
     "description": "Natural-language guidance describing the server and its features.\n\nThis can be used by clients to improve an LLM's understanding of\navailable tools (e.g., by including it in a system prompt). It should\nfocus on information that helps the model use the server effectively\nand should not duplicate information already in tool descriptions.",
     "type": "string"
   },
   "resultType": {
     "description": "Indicates the type of the result, which allows the client to determine\nhow to parse the result object.\n\nServers implementing this protocol version MUST include this field.\nFor backward compatibility, when a client receives a result from a\nserver implementing an earlier protocol version (which does not include\nresultType), the client MUST treat the absent field as \"complete\".",
     "type": "string"
   },
   "supportedVersions": {
     "description": "MCP Protocol Versions this server supports. The client should choose a\nversion from this list for use in subsequent requests.",
     "type": "array",
     "items": {
       "type": "string"
     }
   },
   "ttlMs": {
     "description": "A hint from the server indicating how long (in milliseconds) the\nclient MAY cache this response before re-fetching. Semantics are\nanalogous to HTTP Cache-Control max-age.\n\n- If 0, The response SHOULD be considered immediately stale,\n  The client MAY re-fetch every time the result is needed.\n- If positive, the client SHOULD consider the result fresh for this many\n  milliseconds after receiving the response.",
     "type": "integer",
     "minimum": 0.0
   }
 }
}

Fields

cache_scope: DiscoverResultCacheScope

Indicates the intended scope of the cached response, analogous to HTTP Cache-Control: public vs Cache-Control: private. - “public”: The response does not contain user-specific data. Any client or intermediary (e.g., shared gateway, caching proxy) MAY cache the response and serve it across authorization contexts. - “private”: The response MAY be cached and reused only within the same authorization context. Caches MUST NOT be shared across authorization contexts (e.g., a different access token requires a different cache).

capabilities: ServerCapabilities

The capabilities of the server.

instructions: Option<String>

Natural-language guidance describing the server and its features. This can be used by clients to improve an LLM’s understanding of available tools (e.g., by including it in a system prompt). It should focus on information that helps the model use the server effectively and should not duplicate information already in tool descriptions.

meta: Option<ResultMetaObject>

result_type: String

Indicates the type of the result, which allows the client to determine how to parse the result object. Servers implementing this protocol version MUST include this field. For backward compatibility, when a client receives a result from a server implementing an earlier protocol version (which does not include resultType), the client MUST treat the absent field as “complete”.

supported_versions: Vec<String>

MCP Protocol Versions this server supports. The client should choose a version from this list for use in subsequent requests.

ttl_ms: u64

A hint from the server indicating how long (in milliseconds) the client MAY cache this response before re-fetching. Semantics are analogous to HTTP Cache-Control max-age. - If 0, The response SHOULD be considered immediately stale, The client MAY re-fetch every time the result is needed. - If positive, the client SHOULD consider the result fresh for this many milliseconds after receiving the response.

Trait Implementations

impl Clone for DiscoverResult

fn clone(&self) -> DiscoverResult

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DiscoverResult

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for DiscoverResult

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl From<DiscoverResult> for ServerResult

fn from(value: DiscoverResult) -> Self

Converts to this type from the input type.

impl From<DiscoverResult> for GenericResult

fn from(value: DiscoverResult) -> Self

Converts to this type from the input type.

impl From<DiscoverResult> for MessageFromServer

fn from(value: DiscoverResult) -> Self

Converts to this type from the input type.

impl Serialize for DiscoverResult

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl TryFrom<ServerResult> for DiscoverResult

type Error = RpcError

The type returned in the event of a conversion error.

fn try_from(value: ServerResult) -> Result<Self, Self::Error>

Performs the conversion.