Agent Skills · Schema

ToolResult

The output returned to an AI agent after executing a tool skill.

Agent SkillsAI AgentsTool UseFunction CallingMCPAgentic AIAutomation

Properties

Name Type Description
type string Content block type, always tool_result.
tool_use_id string The id of the tool_use block this result corresponds to.
content object The result content returned from the tool. Can be a string or array of content blocks.
is_error boolean When true, indicates the tool execution returned an error.
View JSON Schema on GitHub

JSON Schema

agent-skills-tool-result-schema.json Raw ↑ 
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://raw.githubusercontent.com/api-evangelist/agent-skills/refs/heads/main/json-schema/agent-skills-tool-result-schema.json",
  "title": "ToolResult",
  "description": "The output returned to an AI agent after executing a tool skill.",
  "type": "object",
  "properties": {
    "type": {
      "type": "string",
      "description": "Content block type, always tool_result.",
      "example": "tool_result"
    },
    "tool_use_id": {
      "type": "string",
      "description": "The id of the tool_use block this result corresponds to.",
      "example": "toolu_01A09q90qw90lq917835lq9"
    },
    "content": {
      "description": "The result content returned from the tool. Can be a string or array of content blocks.",
      "oneOf": [
        { "type": "string" },
        {
          "type": "array",
          "items": {
            "type": "object",
            "properties": {
              "type": { "type": "string" },
              "text": { "type": "string" }
            }
          }
        }
      ],
      "example": "72°F and sunny in San Francisco, CA"
    },
    "is_error": {
      "type": "boolean",
      "description": "When true, indicates the tool execution returned an error.",
      "example": false
    }
  },
  "required": ["type", "tool_use_id", "content"]
}