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v9.1.1
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HarnessToolOptions

import type { HarnessToolOptions } from "@elie-laloum/outpost";

Parameters and properties

Section titled “Parameters and properties”
  • nameRequired
    string
    Unique tool name of 1 to 64 letters, digits, underscores or hyphens, shown to the model.
  • descriptionRequired
    string
    Nonempty explanation the model reads to decide when and how to call the tool.
  • inputRequired
    Readonly<Record<string, unknown>> | StandardJsonSchema<Input>
    Input schema: a JSON Schema object checked with the built-in subset (type, properties, required, additionalProperties, items, enum, const and length, range and item-count bounds), or a Standard Schema that exports JSON Schema, such as Zod 4. Other keywords are rejected at definition.
  • readOnlyOptional
    boolean | undefined
    Marks a tool without side effects, default false. Read-only calls can run in parallel, and response repair turns keep only read-only tools.
  • resourcesOptional
    ((input: Input) => ToolResources) | undefined
    Describe the paths and command of a validated input so permission rules can match them. Custom tools without it only match by name.
  • executeRequired
    (input: Input, context: HarnessToolContext) => ToolOutput | Promise<ToolOutput>
    Runs the call with validated input and its context, and returns text or { content, isError }. A thrown error is handled by toolExecution.onError; results over 100000 characters are cut before reaching the model.

Signature

Section titled “Signature”
export interface HarnessToolOptions<Input> {
  readonly name: string;
  readonly description: string;
  readonly input: StandardJsonSchema<Input> | JsonSchema;
  readonly readOnly?: boolean;
  resources?(input: Input): ToolResources;
  execute(
    input: Input,
    context: HarnessToolContext,
  ): ToolOutput | Promise<ToolOutput>;
}
Section titled “Related contracts”