Strict Tool Implementer

Overview

This skill implements Anthropic's strict tool use mode for reliable agentic systems. With strict: true, tool input parameters are guaranteed to match your schema—no validation needed in your tool functions.

What This Skill Provides:

• Production-ready tool schema design
• Multi-tool workflow patterns
• Agentic system architecture
• Validation and error handling
• Complete agent implementation examples

Prerequisites:

• Decision made via structured-outputs-advisor
• Model: Claude Sonnet 4.5 or Opus 4.1
• Beta header: structured-outputs-2025-11-13

When to Use This Skill

Use for:

• Building multi-step agentic workflows
• Validating function call parameters
• Ensuring type-safe tool execution
• Complex tools with nested properties
• Critical operations requiring guaranteed types

NOT for:

• Extracting data from text/images → json-outputs-implementer
• Formatting API responses → json-outputs-implementer
• Classification tasks → json-outputs-implementer

Response Style

• Tool-focused: Design tools with clear, validated schemas
• Agent-aware: Consider multi-tool workflows and composition
• Type-safe: Guarantee parameter types for downstream functions
• Production-ready: Handle errors, retries, and monitoring
• Example-driven: Provide complete agent implementations

Workflow

Phase	Description	Details
1	Tool Schema Design	→ workflow/phase-1-schema-design.md
2	Multi-Tool Agent Implementation	→ workflow/phase-2-implementation.md
3	Error Handling & Validation	→ workflow/phase-3-error-handling.md
4	Testing Agent Workflows	→ workflow/phase-4-testing.md
5	Production Agent Patterns	→ workflow/phase-5-production.md

Quick Reference

Schema Template

{
    "name": "tool_name",
    "description": "Clear description",
    "strict": True,
    "input_schema": {
        "type": "object",
        "properties": {...},
        "required": [...],
        "additionalProperties": False
    }
}

Supported Schema Features

✅ Basic types, enums, format strings, nested objects/arrays, required fields

❌ Recursive schemas, min/max constraints, string length, complex regex

Reference Materials

• Common Agentic Patterns
• Success Criteria

Related Skills

• structured-outputs-advisor - Choose the right mode
• json-outputs-implementer - For data extraction use cases