Video Tutorial
What Are Tools?
A tool is a REST API definition that the LLM can invoke at runtime. Typical use cases:- Call your own backend endpoints
- Trigger n8n automations
- Sync data with a CRM
- Fetch data from external APIs (weather, pricing, availability, etc.)
- Write/update/read data using Rest API
- which tool to call
- when to call it
- what parameters to send
- Your prompts: node-level instructions in simple english (or any language)
- Tool name
- Tool description
- Parameter definitions
Defining Tools
1. Tool Name
- Must be clear and action-oriented.
-
Examples:
capture_lead_interest,fetch_weather, ‘create_crm_contact’, etc
2. Tool Description
- Extremely important
- This is how the LLM decides when to use the tool.
- Write it in plain, explicit English.
3. Endpoint Configuration
- Full URL (must include
http://orhttps://) - Supports REST methods
Common mistake: forgetting https:// in the URL.
4. Authentication & Headers
- Add custom authentication
- Add custom headers
- Works with internal services and third-party APIs
5. Parameters
Each parameter must have:- Name
- Type
- Description
- Required/Optional flag
- Start with string parameters when possible
- Be explicit in what the value represents
- Mark only truly mandatory fields as required
- interest (string): “Set to true if the user clearly shows intent to buy or wants follow-up. Otherwise false.”
Attaching Tools to Workflow Nodes
- You can attach multiple tools to a single node
- All the tools that you have created will be available for selection in the node
- Tools are only callable when attached to that node
- The LLM will choose which one to call
Tool Invocation Logic (How the LLM Thinks)
The LLM considers:- User’s spoken intent
- Node prompt instructions
- Tool name and description
- Parameter descriptions
- Missed tool calls
- Wrong parameters
- Hallucinated values
Key Best Practices
- Name tools clearly
- Write detailed, action-based descriptions
- Keep parameters simple at first
- Always include http/https in URLs
- Use plain English in node instructions
- Attach only relevant tools to each node