How do I create a check calendar availability tool for an AI agent?

Last updated: November 5, 2026

A check calendar availability tool lets an AI agent look up open Cal.com time slots before suggesting meeting times. The tool must be created, configured, selected for the agent, and referenced in the agent instructions.

Before you start

  • Make sure your Cal.com API key is available or already configured for your organization.

  • Find the Cal.com event type ID for the meeting type the agent should check.

  • Decide which timezone the tool should use.

Steps

  1. Open Agents.

  2. Click Tools.

  3. Select Create tool.

  4. Choose Check calendar availability (Cal.com).

  5. Enter a tool name and optional description.

  6. Click Save.

  7. Confirm or update the tool label and description.

  8. Confirm the Cal.com API key is populated.

  9. Enter the Cal.com event type ID.

  10. Optionally set the timezone using a format like America/New_York.

  11. Save the tool.

  12. Open the agent that should use the tool.

  13. Add the tool in Select tools.

  14. In the agent instructions, tell the agent when to check availability and what to do with the returned times.

  15. Save the agent.

Tips

  • Tell the agent to check availability before offering meeting times.

  • Use a clear timezone to avoid confusing customers in different regions.

  • Pair this tool with a booking tool when the agent should also schedule the meeting.

Troubleshooting

  • No availability is returned: Verify the Cal.com event type ID.

  • The tool fails: Confirm the Cal.com API key is valid.

  • Times look incorrect: Check the configured timezone.

  • The agent does not use the tool: Confirm the tool is selected and named in the agent instructions.