> ## Documentation Index
> Fetch the complete documentation index at: https://docs.latitude.so/llms.txt
> Use this file to discover all available pages before exploring further.

# Tool calls

> Inspect the tools your agent invoked, including their inputs, outputs, and errors, as spans inside a trace.

# Tool calls

A **tool call** is a [span](./spans) that records a function or tool your agent invoked while handling a request. Tool-call spans let you see which tools ran, what arguments they received, what they returned, and whether they failed.

## What a tool-call span captures

* the **tool name** that was invoked
* the **input** arguments the agent passed
* the **output** the tool returned
* **error status** when the call failed
* timing and duration

Latitude renders tool input and output as formatted JSON when it can, and as a plain code block otherwise, so you can read structured arguments and results directly.

## Inspecting tool calls

Open a trace and find the tool-call spans in its span tree. Expanding one shows the arguments the agent sent and the result it received. This is the fastest way to answer questions such as:

* Did the agent call the right tool for the request?
* Were the arguments well formed?
* Did the tool return what the agent expected, or did it error?
* Is the agent looping between tools instead of making progress?

## Next steps

* [Spans](./spans): the building block a tool call is recorded as
* [Traces](./traces): the full interaction that contains the tool calls
* [Search](../search/overview): find traces by tool behaviour and other signals