ToolResult is a JSON Structure definition published by Agent Skills, describing 4 properties, of which 3 are required. It conforms to the https://json-structure.org/meta/core/v0/# meta-schema.
{
"$schema": "https://json-structure.org/meta/core/v0/#",
"$id": "https://raw.githubusercontent.com/api-evangelist/agent-skills/refs/heads/main/json-structure/agent-skills-tool-result-structure.json",
"name": "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\u00b0F 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"
]
}
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