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Your First Generated Tool

MCP tool definitions are generated from the Semantic Manifest. Each manifest operation becomes a callable tool that agent runtimes can discover and invoke.

You don't write them. @web-axag/compiler emits them on every build, or run npx @web-axag/cli generate src --tools tools/tool-registry.json in CI.

From Manifest to Tool​

Given the manifest entry from the previous step, the generated MCP tool definition is:

MCP tool — product_search
{
  "name": "product_search",
  "description": "Search the product catalog by text query with optional filters",
  "input_schema": {
    "type": "object",
    "properties": {
      "query": {
        "type": "string",
        "description": "Free-text search query for product name, description, or SKU"
      },
      "category": { "type": "string", "description": "Filter by product category" },
      "price_min": { "type": "number", "description": "Minimum price filter" },
      "price_max": { "type": "number", "description": "Maximum price filter" }
    },
    "required": ["query"]
  },
  "metadata": {
    "action_type": "read",
    "risk_level": "none",
    "idempotent": true,
    "confirmation_required": false,
    "approval_required": false,
    "source_intent": "product.search",
    "source_entity": "product"
  }
}

Tool Structure​

MCP tool definitions contain:

FieldPurpose
nameUnique identifier derived from the intent (product.search → product_search)
descriptionHuman-readable description for agent planning
input_schemaJSON Schema for tool parameters
metadataAction type, risk, idempotency, confirmation, and the source intent

How Agents Use This Tool​

An agent runtime:

  1. Discovers product_search in the tool registry
  2. Plans to use it based on user request (e.g., "Find red running shoes under $100")
  3. Constructs parameters: { "query": "red running shoes", "price_max": 100 }
  4. Validates that required parameters are present
  5. Checks safety — read operation, no risk, no confirmation needed
  6. Executes the tool
  7. Returns results to the user

Next Steps​