Tools & Custom Actions - Burki Voice AI Docs

Tools empower your AI assistants to perform real actions during calls—from built-in actions like call transfers to custom integrations with your APIs, Python functions, and AWS Lambda services.

Tool Types Overview

Burki Voice AI supports three main categories of tools:

🔧 Built-in Tools

Ready-to-use actionsCall transfers, graceful endings, and essential call management features.

🛠️ Custom Tools

Your integrationsConnect to APIs, run Python code, or trigger Lambda functions during calls.

📚 Tool Library

Reusable & ShareableCreate once, use across multiple assistants. Build your organization’s tool ecosystem.

Built-in Tools

End Call Tool

What it does: Allows the assistant to end calls automatically when appropriate.Configuration:

Enable/Disable: Toggle the tool on or off
Scenarios: Define when the assistant should end calls
Custom Message: What to say before ending the call

Example Scenarios:

“Customer says goodbye”
“Issue resolved”
“Request completed”
“Complaint escalated”

Use specific scenarios to help the AI understand when it’s appropriate to end a call. Be clear about completion criteria.

Transfer Call Tool

What it does: Transfers calls to human agents or other phone numbers.Configuration:

Enable/Disable: Toggle the tool on or off
Transfer Numbers: List of phone numbers to transfer to
Scenarios: Define when transfers should happen
Transfer Type: Choose cold/blind transfer or warm/briefed transfer
Agent Confirmation: For warm transfer, require the agent to confirm before the caller is connected
Unavailable Message: For warm transfer, what the caller hears if no agent is available

Example Transfer Numbers:

+1234567890 (Sales team)
+0987654321 (Technical support)
+1122334455 (Manager)

Example Scenarios:

“Technical issue beyond AI capability”
“Billing inquiry”
“Escalation request”
“Customer requests human agent”

Make sure transfer numbers are valid and staffed. Failed transfers create poor customer experiences.

Cold vs Warm Transfers

Mode	What happens	Best for
Cold transfer	Caller is transferred immediately to the destination number.	Simple reception, queue handoffs, sales desks, and cases where agent context is not required.
Warm transfer	Caller waits while the human agent receives an AI-generated summary before connection.	Escalations, support, healthcare/admin, or sales calls where context improves handoff quality.

Warm transfer settings:

agent_confirmation: the agent must accept before Burki connects the caller.
unavailable_message: message spoken or played to the caller when the warm transfer cannot complete.
transfer_call_message: configured in Calling, spoken before transfer starts.

Example transfer configuration:

{
  "tools_settings": {
    "transfer_call": {
      "enabled": true,
      "scenarios": [
        "caller asks for a human agent",
        "billing dispute requires account team"
      ],
      "transfer_numbers": ["+18005551212"],
      "transfer_type": "warm",
      "agent_confirmation": true,
      "unavailable_message": "I could not reach an agent right now. I can take a message or schedule a callback."
    }
  }
}

DTMF Solver and SMS Tools

The edit-assistant page also exposes:

DTMF Solver: define scenarios where the assistant should press touch-tone digits to navigate an IVR or enter a code.
Send SMS: define scenarios and an optional default message. If no default message is set, the AI composes the SMS from context.

SMS requires a valid messaging provider setup and carrier compliance where applicable.

Custom Tools

What they are: Powerful, reusable integrations that extend your assistant’s capabilities.Three Types Available:

Endpoint Tools: Call external APIs during conversations
Python Function Tools: Execute custom Python code with full library access
AWS Lambda Tools: Trigger serverless functions for scalable processing

Key Benefits:

Reusable: Create once, use across multiple assistants
Secure: Built-in sandboxing and input validation
Flexible: Support any API, database, or business logic
Scalable: From simple lookups to complex workflows

Custom tools are managed through the Tools Library in your dashboard. Create, test, and assign tools to assistants with a few clicks.

How to Configure Tools

Step 1: Enable Tools

Go to your assistant’s configuration
Navigate to the Tools section
Enable the tools you want to use
Configure each tool’s settings

Start with basic tools (End Call, Transfer Call) before implementing custom tools.

Step 2: Define Scenarios

For End Call Tool:

List specific situations when calls should end
Be clear about completion criteria
Consider both successful and unsuccessful outcomes

For Transfer Call Tool:

Define when human intervention is needed
Specify different transfer destinations for different scenarios
Include escalation triggers

Example Scenarios Format:

customer says goodbye, issue resolved, request completed, complaint escalated

Step 3: Set Custom Messages

End Call Messages:

Professional and friendly
Confirm completion of the interaction
Leave a positive impression

Transfer Messages:

Explain what’s happening
Set expectations for wait time
Reassure the customer

Examples:

End Call: “Thank you for calling! I’ve helped resolve your issue. Have a great day!”
Transfer: “I’m connecting you with a specialist who can better assist you. Please hold for just a moment.”

Best Practices

Test thoroughly: Try different scenarios to ensure tools work as expected
Keep scenarios specific: Vague scenarios lead to unpredictable behavior
Monitor usage: Track when and why tools are being used
Update regularly: Refine scenarios based on real call data
Train your team: Ensure human agents are prepared for transfers

Tool Usage Examples

Customer Service Scenario

Setup:

End Call Tool: Enabled
Transfer Call Tool: Enabled
Transfer Numbers: Support team, billing department

Scenarios:

End Call: “issue resolved, customer satisfied, information provided”
Transfer: “billing question, technical problem, escalation requested”

Result: AI handles simple inquiries but transfers complex issues to appropriate teams.

Sales Scenario

Setup:

End Call Tool: Enabled
Transfer Call Tool: Enabled
Transfer Numbers: Sales team, manager

Scenarios:

End Call: “information provided, not interested, callback scheduled”
Transfer: “ready to purchase, complex pricing question, wants to speak to sales”

Result: AI qualifies leads and transfers hot prospects to sales team.

Troubleshooting

Common Tool Issues

Tools not triggering: Check scenario definitions are specific enough
Wrong transfers: Verify phone numbers are correct and active
Premature call endings: Refine end call scenarios to be more specific
Failed transfers: Ensure target numbers can receive calls
Unclear messages: Test custom messages with real users

Use call recordings and transcripts to analyze tool usage and improve configurations.

The custom tools reference (HTTP endpoints, Python functions, AWS Lambda discovery, IAM, testing checklists, and integration examples) is on a dedicated page so this guide loads faster.

Custom tools — deep dive

Full configuration for endpoint tools, Python sandboxes, Lambda and discovery, validation, assignment, and real-world examples.

API Reference

For programmatic tool management, see the API documentation:

Tool Management API

Create, update, and manage tools programmatically

Tool Assignment API

Assign tools to assistants via API

Documentation Index

​Tool Types Overview

🔧 Built-in Tools

🛠️ Custom Tools

📚 Tool Library

​Built-in Tools

​Cold vs Warm Transfers

​DTMF Solver and SMS Tools

​How to Configure Tools

​Best Practices

​Tool Usage Examples

​Troubleshooting

Custom tools — deep dive

​API Reference

Tool Management API

Tool Assignment API

Tool Types Overview

Built-in Tools

Cold vs Warm Transfers

DTMF Solver and SMS Tools

How to Configure Tools

Best Practices

Tool Usage Examples

Troubleshooting

API Reference