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# Struct Tool Call Params

> Builder parameters for `tool_call`.

Generated from `cargo doc --no-deps -p nemo-relay-builtins -p nemo-relay-diagnostics -p nemo-relay-logging -p nemo-relay-plugin-host -p nemo-relay-codecs -p nemo-relay -p nemo-relay-runtime -p nemo-relay-model-pricing -p nemo-relay-resource-metrics -p nemo-relay-observability -p nemo-relay-adaptive -p nemo-relay-pii-redaction -p nemo-relay-ffi -p nemo-relay-types -p nemo-relay-plugin -p nemo-relay-worker-proto -p nemo-relay-worker`.

<pre />

Builder parameters for [`tool_call`](/reference/api/rust-library-reference/nemo-relay/tool/fn-tool-call).

## Fields

### `name: &'a str`

Tool name recorded on the emitted lifecycle event.

### `args: Value`

Raw tool arguments associated with the span.

### `parent: Option<&'a ScopeHandle>`

Optional explicit parent scope.

### `attributes: ToolAttributes`

Tool attribute bitflags applied to the span.

### `data: Option<Value>`

Optional application payload stored on the handle but not emitted as Agent Trajectory Observability Format (ATOF) data.

### `metadata: Option<Value>`

Optional JSON metadata recorded on the start event.

### `tool_call_id: Option<String>`

Optional provider-specific correlation identifier.

### `timestamp: Option<DateTime<Utc>>`

Optional timestamp captured as the handle start time and reused by the emitted start event. When omitted, the current UTC time is used.

## Implementations

### `impl<'a> ToolCallParams<'a>`

<pre />

#### `builder`

<pre />

Create a builder for building `ToolCallParams`. On the builder, call `.name(...)`, `.args(...)`, `.parent(...)`(optional), `.attributes(...)`(optional), `.data(...)`(optional), `.metadata(...)`(optional), `.tool_call_id(...)`(optional), `.timestamp(...)`(optional) to set the values of the fields. Finally, call `.build()` to create the instance of `ToolCallParams`.