Tool Creator Skill

Metadata

• Name:

  tool_creator

• Description: Convert reusable task logic into durable callable tools and register them for future chats

Purpose

Turn user-requested workflows into reusable function/tool calls that can be discovered and executed later (same chat or new chat).

This skill creates long-lived assets under the agent skill/tool config area (for example

~/codex/skills/*

) so the agent can reuse them across sessions.

When To Trigger

• A task includes repeatable logic (data fetch, transform, orchestration, validation, business rules, workflow steps).
• A user asks for a feature that can be represented as a callable operation.
• Tool discovery did not find a suitable existing tool.
• A partial tool exists but needs extension/versioning.

Required Workflow

1. Understand intent and normalize it into an operation name.

   Example:

   • User asks: "When user enters Contacts page, query contact list."
   • Operation:

     query_user_contacts

2. Decompose into implementation layers and check for existing components first:

   • Data model
   • Repository / data source
   • Service / use case function
   • Tool interface (call schema)

3. Create only missing pieces:

   • If model exists, reuse it.
   • If repository exists, reuse it.
   • If business function exists, wrap it.
   • If nothing exists, generate all layers.

4. Ensure the callable function returns typed, stable output and handles common failures.

5. Package as a tool artifact:

   • Tool name, description, input schema, output schema
   • Example invocation
   • Dependency notes
   • Version (

     v1

     ,

     v2

     , etc.) when extending behavior

6. Persist for cross-chat reuse:

   • Save tool spec and implementation notes under the configured skills/tools directory.
   • Update tool registry/index so tool discovery can find it by intent.

Flutter Example Flow (Reference)

Given: "Fetch user contacts when Contact page opens."

1. Model (if missing):

   UserContact

2. Repository method (if missing):

   Future<List<UserContact>> getContacts()

3. Use-case function (if missing):

   queryUserContacts(repo)

4. Tool wrapper:

   query_user_contacts

5. Register in tool index for future retrieval.

Output Contract

This skill output MUST include all of the following:

• Reuse decision (what already existed vs what was created)
• Callable operation signature
• Tool definition (name, input, output)
• Registry update target/path
• Persistence location for future chats

Persistence and Location Rules

• Default location pattern: agent config skills/tools directory (example:

  ~/codex/skills/*

  ).
• Tool artifacts should be durable and discoverable by

  tool_discovery

  .
• Avoid chat-local only outputs when the logic is reusable.

Guardrails

• Do not duplicate an existing tool with identical intent.
• Prefer extending/versioning an existing tool for near-match requests.
• Keep tool names action-oriented and domain-specific (

  query_user_contacts

  ,

  create_invoice_draft

  ).

Key Rule

If a workflow is reusable, convert it into a persistent callable tool before finishing the task.