Struct ToolExecutionStartData 

pub struct ToolExecutionStartData {

    pub arguments: Option<Value>,
    pub display_verbatim: Option<bool>,
    pub fusion: Option<FusionAttribution>,
    pub mcp_config_server_name: Option<String>,
    pub mcp_config_source: Option<McpServerSource>,
    pub mcp_server_name: Option<String>,
    pub mcp_tool_name: Option<String>,
    pub mcp_transport: Option<McpServerTransport>,
    pub model: Option<String>,
    pub rte: Option<bool>,
    pub shell_tool_info: Option<ToolExecutionStartShellToolInfo>,
    pub tool_call_id: String,
    pub tool_description: Option<ToolExecutionStartToolDescription>,
    pub tool_name: String,
    pub turn_id: Option<String>,
    /* private fields */
}

Session event “tool.execution_start”. Tool execution startup details including MCP server information when applicable

Fields

arguments: Option<Value>

Arguments passed to the tool

display_verbatim: Option<bool>

When true, the tool output should be displayed expanded (verbatim) in the CLI timeline

fusion: Option<FusionAttribution>

Experimental HydraFusion attribution for this tool execution.

Experimental. This type is part of an experimental wire-protocol surface and may change or be removed in future SDK or CLI releases.

mcp_config_server_name: Option<String>

Preferred lookup name for the MCP server hosting this tool: the configured (namespaced) config-map key when the tool carries one, otherwise the display name from mcpServerName. Present when the tool is an MCP tool; this is the name unrestricted provenance telemetry hashes so it joins with mcp_server_setup, which keys off the configured name too.

mcp_config_source: Option<McpServerSource>

Where the MCP server’s configuration came from (user, workspace, plugin, or builtin), when the tool is an MCP tool and the server is configured

mcp_server_name: Option<String>

Name of the MCP server hosting this tool, when the tool is an MCP tool

mcp_tool_name: Option<String>

Original tool name on the MCP server, when the tool is an MCP tool

mcp_transport: Option<McpServerTransport>

Transport the MCP server hosting this tool is connected over, when the tool is an MCP tool and the server is configured

model: Option<String>

Model identifier that generated this tool call

rte: Option<bool>

Per-request treatment/eligibility signal returned by the Copilot API in the X-GitHub-Copilot-Request-TE response header for the associated model call; false when the header was absent or unparseable.

shell_tool_info: Option<ToolExecutionStartShellToolInfo>

Shell-tool path hints derived from the command at start time for shell tools (bash/powershell/local_shell). Produced by the same shell-aware extractor as PermissionRequestShell.possiblePaths, so it is present even when the command is auto-approved and no permission request fires. Absent for non-shell tools.

tool_call_id: String

Unique identifier for this tool call

tool_description: Option<ToolExecutionStartToolDescription>

Tool definition metadata, present for MCP tools with MCP Apps support

tool_name: String

Name of the tool being executed

turn_id: Option<String>

Identifier for the agent loop turn this tool was invoked in, matching the corresponding assistant.turn_start event

Trait Implementations

impl Clone for ToolExecutionStartData

fn clone(&self) -> ToolExecutionStartData

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ToolExecutionStartData

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

Formats the value using the given formatter.

impl Default for ToolExecutionStartData

fn default() -> ToolExecutionStartData

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ToolExecutionStartData

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for ToolExecutionStartData

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

where __S: Serializer,

Serialize this value into the given Serde serializer.