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

# Tools

> Enhance your assistant with knowledge retrieval, API calls, endpoint calls, call transfer, call hold, and conversation-ending actions.

Tools let your assistant take actions during a conversation. The assistant decides when to call a tool from the tool name, description, and argument schema you configure.

## Available tools

<CardGroup cols={2}>
  <Card title="Knowledge Retrieval" icon="book-open" href="/assistants/tools/add-knowledge-tool">
    Query a Rapida knowledge base and return relevant document chunks to the assistant.
  </Card>

  <Card title="API Request" icon="zap" href="/assistants/tools/add-api-tool">
    Call an external HTTP API for CRM lookups, booking flows, inventory checks, and other backend actions.
  </Card>

  <Card title="Endpoint (LLM Call)" icon="cpu" href="/assistants/tools/add-endpoint-tool">
    Invoke a separate Rapida endpoint for specialized prompt, classification, extraction, or reasoning tasks.
  </Card>

  <Card title="Transfer Call" icon="phone-forwarded" href="/assistants/tools/add-transfer-call-tool">
    Hand an active phone call to a human agent, queue, phone number, or SIP target.
  </Card>

  <Card title="Put On Hold" icon="phone" href="/assistants/tools/add-put-on-hold-tool">
    Pause the conversation while a longer-running lookup or backend action completes.
  </Card>

  <Card title="End of Conversation" icon="phone-off" href="/assistants/tools/add-end-of-conversation-tool">
    End the session when the assistant determines the conversation is complete.
  </Card>
</CardGroup>

<Note>
  Tool names must use only letters, numbers, and underscores. Write descriptions that tell the model exactly when to call the tool and what information to collect first.
</Note>

## How tools run

Most tools follow the same runtime flow:

1. The assistant selects a tool based on the conversation and the tool description.
2. The assistant fills the tool fields from conversation context.
3. Rapida executes the configured action or sends the channel-level directive.
4. The tool result is recorded in conversation logs and used by the assistant when the conversation continues.

Call-control tools such as [Transfer Call](/assistants/tools/add-transfer-call-tool) and [End of Conversation](/assistants/tools/add-end-of-conversation-tool) can end or redirect the active call instead of returning data to the model.