Agent Skills · JSON Structure

Agent Skills Tool Call Structure

An AI agent's invocation of a tool skill with specific input parameters.

Type: object Properties: 4 Required: 4
Agent SkillsAI AgentsTool UseFunction CallingMCPAgentic AIAutomation

ToolCall is a JSON Structure definition published by Agent Skills, describing 4 properties, of which 4 are required. It conforms to the https://json-structure.org/meta/core/v0/# meta-schema.

Properties

id type name input

Meta-schema: https://json-structure.org/meta/core/v0/#

JSON Structure

agent-skills-tool-call-structure.json Raw ↑ 
{
  "$schema": "https://json-structure.org/meta/core/v0/#",
  "$id": "https://raw.githubusercontent.com/api-evangelist/agent-skills/refs/heads/main/json-structure/agent-skills-tool-call-structure.json",
  "name": "ToolCall",
  "description": "An AI agent's invocation of a tool skill with specific input parameters.",
  "type": "object",
  "properties": {
    "id": {
      "type": "string",
      "description": "Unique identifier for this tool call instance.",
      "example": "toolu_01A09q90qw90lq917835lq9"
    },
    "type": {
      "type": "string",
      "description": "Content block type, always tool_use.",
      "example": "tool_use"
    },
    "name": {
      "type": "string",
      "description": "Name of the tool being called.",
      "example": "get_weather"
    },
    "input": {
      "type": "object",
      "description": "Input parameters provided to the tool, conforming to the tool's input_schema.",
      "example": {
        "location": "San Francisco, CA"
      }
    }
  },
  "required": [
    "id",
    "type",
    "name",
    "input"
  ]
}