structured-output-and-tool-calling

Validate and repair LLM JSON outputs and execute tool calls with retries.

1|Updated Jun 9, 2026
One-click install
npx skills add https://github.com/jpoindexter/design-and-ai-skills --skill structured-output-and-tool-calling
Or copy as Structured Prompt for Agent
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Skill: structured-output-and-tool-calling
Source: https://github.com/jpoindexter/design-and-ai-skills/tree/main/ai-engineering-skills/structured-output-and-tool-calling
Command: npx skills add https://github.com/jpoindexter/design-and-ai-skills --skill structured-output-and-tool-calling

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes scripts (resource) and references (resource) components.

What problem does it solve?

This Skill ensures that LLMs provide structured, valid output and reliably execute tool calls, reducing errors and ensuring reliable data processing and actions.

Core Features & Use Cases

  • Constrained Decoding: Enforces structural validity in JSON output.
  • Validation & Repair Loop: Validates and repairs output for semantic validity.
  • Idempotency & Fallbacks: Ensures retries don't lead to unintended effects and provides fallbacks for errors.
  • Tool Contracts: Defines clear contracts for tool calls to LLMs.
  • Idempotency Keys: Ensures write actions are safe to retry.
  • Evals for Reliability: Continuously evaluates output for accuracy.
  • Use Case: Ideal for scenarios where LLMs are integrated with databases, APIs, or other tools, requiring reliable and structured data exchange.

Quick Start

Use the structured-output-and-tool-calling skill to validate and process JSON output from the LLM response with 'validate_response --input "input_data.json"'

Frequently Asked Questions about structured-output-and-tool-calling

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I ensure LLM structured output is valid JSON for API integrations?

To ensure LLM structured output is valid JSON, you can enforce constrained decoding and apply a validation and repair loop. This approach guarantees semantic validity and reliable data exchange for database or API tool calls.

What is the best way to handle LLM tool calling retries without unintended side effects?

The best way to handle LLM tool calling retries safely is by using idempotency keys. This ensures that retried write actions do not lead to unintended duplicate effects, while defined fallbacks manage errors during execution.

How do tool contracts improve reliability when integrating LLMs with external APIs?

Tool contracts improve LLM API integration reliability by defining clear execution parameters for tool calls. This structured approach ensures the LLM provides predictable inputs, reducing errors during data processing and external actions.

Can I automatically repair invalid JSON output generated by an LLM?

Yes, you can automatically repair invalid JSON output generated by an LLM using a validation and repair loop. This mechanism checks for semantic validity and fixes structural errors to ensure deterministic outcomes.

Why do I need evals for structured LLM outputs and tool calls?

You need evals for structured LLM outputs and tool calls to continuously evaluate accuracy and reliability. This ongoing testing ensures that JSON validation and constrained decoding maintain precise, deterministic outcomes over time.