Tool Discovery Skill

Metadata

• Name:

  tool_discovery

• Description: Detect, rank, and invoke reusable tools for each prompt before creating new implementations

Purpose

For every user prompt, determine whether an existing callable tool can fulfill the request. Reuse first; create new only when necessary.

When to Trigger

• On every user prompt (mandatory first-pass behavior).

Required Workflow

1. Parse intent into candidate actions:

   • Primary action (what user wants done)
   • Domain entities (users, contacts, orders, etc.)
   • Constraints (filters, pagination, timing, context)

2. Search tool registry/index and tool specs in the configured skills directory (for example

   ~/codex/skills/*

   ).

3. Match and rank:

   • Exact intent match -> use directly
   • Close/partial match -> adapt arguments or select latest compatible version
   • No match -> trigger

     tool_creator

4. Invoke tool using its declared schema and pass normalized arguments.

5. Post-process output for the user's requested format (UI mapping, API response shaping, narrative explanation).

Invocation Contract

{
  "tool": "query_user_contacts",
  "arguments": {
    "page": 1,
    "limit": 50
  }
}

Priority Rules

1. Always attempt tool reuse before writing inline logic.
2. Never duplicate existing tools with the same intent.
3. If a partial tool exists, prefer extension/versioning over creating a separate duplicate.
4. If no suitable tool exists, immediately route to

   tool_creator

   .

Flutter Example (Reference)

Prompt: "When opening Contacts page, fetch user contact list."

• Discovery finds

  query_user_contacts

  -> invoke it.
• If missing -> trigger

  tool_creator

  to create:
  • model (if needed)
  • repository method (if needed)
  • use-case function
  • tool wrapper and registry entry
• Then call the new tool.

Output Requirement

• Must produce one of:
  • A concrete tool invocation (tool name + arguments), or
  • A

    tool_creator

    handoff request with normalized intent and requirements.
• Must include brief reason for match decision (exact / partial / none).

Key Rule

Every prompt must go through tool discovery before implementation begins.