tool_call
A single tool invocation made by an agent during a message. Captures the tool name, input arguments, and the result that came back. Tool calls are first-class entities so you can query “every time Claude ran Grep on this repo” or “every tool call that errored.” any agent framework that records tool use.
| Metadata | Value |
|---|---|
| Plural | tool_calls |
| Subtitle field | name |
| Identity | platform, id |
Fields
Section titled “Fields”| Field | Type |
|---|---|
name | string |
input | text |
output | text |
isError | boolean |
durationMs | integer |
Relations
Section titled “Relations”| Relation | Target |
|---|---|
platform | product |
from | actor |
inMessage | message |
repliesTo | tool_call |
Prior art
Section titled “Prior art”External standards this shape draws from or aligns with. See Shape design principles for how prior art informs shape design.
- Anthropic Tool Use API — Our name/input/output/isError map to tool_use/tool_result blocks in Claude’s message API.
- OpenAI Function Calling / tool_calls — Our name/input = function.name/function.arguments; output is the tool-result message content.
- OpenTelemetry GenAI semconv — Emerging observability standard. Our durationMs/isError align with gen_ai.tool.* span attributes.