gcwing Product App Tool Component Skill
Use this skill when the Product App needs a structured callable capability that can be invoked by the app or its app-private Agent. A Tool Component is an app-private tool contract for one Product App unless the user explicitly asks for a reusable shared capability outside App Builder's default delivery boundary.
Development Boundary
- Start from the current package facts and generated Tool scaffold. If the tool is missing, create it with
CreateProductAppComponentusing kindtool. - Define the contract in
source/tool.schema.json: name, description, input schema, and output schema. - Implement behavior in
source/tool.js, keeping outputs structured and stable. - Keep visible UI rendering in app-private surfaces and broad integration/service-action boundaries in Bridge Components.
- Keep permissions limited to the tool's declared behavior and callers.
Key Decisions
- Use a Tool Component when callers need a typed function-like capability, not when they need a visible screen or a long-running integration boundary.
- Design schemas from caller needs: required fields, result shape, error shape, and deterministic examples.
- Keep side effects explicit. If the tool writes files, runs shell commands, or calls network services, that must be reflected in permissions and validation.
- Use
product-app-apiwhen wiring the tool to Product App backend calls, permissions, or runtime evidence.
Validation
- Refresh the Product App lock after package or component graph changes.
- Run Product App package validation.
- Execute a capability preview or concrete fixture when allowed.
- If execution is not allowed or no fixture exists, validate the contract and report that behavior execution remains unverified.