> ## Documentation Index
> Fetch the complete documentation index at: https://grandcentral.backbase.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Understanding tool discovery

> How to discover and understand MCP tools in Grand Central

Learn how Grand Central exposes banking operations as discoverable MCP tools.

## Tool discovery

Your AI agent can discover all available tools through the MCP protocol:

```json theme={"system"}
{
  "jsonrpc": "2.0",
  "method": "tools/list",
  "id": 1
}
```

Response includes tool metadata:

```json theme={"system"}
{
  "jsonrpc": "2.0",
  "result": {
    "tools": [
      {
        "name": "getCustomerProfile",
        "description": "Retrieve customer contact information and preferences",
        "inputSchema": {
          "type": "object",
          "properties": {
            "customerId": {
              "type": "string",
              "description": "Unique customer identifier"
            }
          },
          "required": ["customerId"]
        }
      }
    ]
  },
  "id": 1
}
```

## Tool metadata

Each tool provides complete metadata for AI agents:

<CardGroup cols={2}>
  <Card title="Name" icon="tag">
    Unique identifier for the tool (e.g., `getCustomerProfile`)
  </Card>

  <Card title="Description" icon="file-lines">
    Clear explanation of what the tool does and when to use it
  </Card>

  <Card title="Input schema" icon="list">
    JSON Schema defining required and optional parameters
  </Card>

  <Card title="Examples" icon="code">
    Sample requests showing proper usage
  </Card>
</CardGroup>

## Tool organization

Grand Central organizes tools by business domain. Your available tools depend on which domains are enabled for your subscription:

<CardGroup cols={3}>
  <Card title="Payments" icon="credit-card">
    Payment processing, transfers, fees, status tracking
  </Card>

  <Card title="Accounts" icon="building-columns">
    Account balances, transactions, details, statements
  </Card>

  <Card title="Customers" icon="users">
    Customer profiles, contact information, preferences
  </Card>

  <Card title="Loans" icon="money-bill">
    Loan eligibility, applications, interest rates
  </Card>

  <Card title="Cards" icon="credit-card-front">
    Card management, limits, transactions
  </Card>

  <Card title="Products" icon="box">
    Available banking products, terms, conditions
  </Card>
</CardGroup>

<Note>
  Available domains and tools depend on what you've enabled in the admin portal for your subscription.
</Note>

## Adding new tools

Need access to additional banking operations? Log into the admin portal and enable them yourself.

**For operations already in the catalog:** Browse the API catalog in the admin portal's MCP Tools section, select the operations you need, configure rate limits and authentication requirements, and enable them. Pre-configured operations are available immediately. The system runs automated validation to ensure security constraints are met.

**For custom operations not yet in the catalog:** Upload or link your OpenAPI specification through the portal. Select which operations to expose as MCP tools, and the system runs automated security validation. Low-risk operations (read-only, public data) enable immediately and appear in discovery responses within minutes. Higher-risk operations (write access, PII exposure) get flagged for automated compliance scanning - these typically complete within 1-3 business days. Platform support is available if you need help with complex specifications or have questions about security requirements.

## Best practices

<CardGroup cols={2}>
  <Card title="Cache tool list" icon="database">
    Cache discovery responses for 5-10 minutes to reduce API calls
  </Card>

  <Card title="Validate parameters" icon="check">
    Use the input schema to validate before invoking tools
  </Card>

  <Card title="Handle errors gracefully" icon="triangle-exclamation">
    Implement retry logic with exponential backoff
  </Card>

  <Card title="Monitor usage" icon="chart-line">
    Track which tools are used most frequently
  </Card>
</CardGroup>

## Next steps

<CardGroup cols={2}>
  <Card title="Tool invocation" icon="play" href="/mcp/capabilities/tool-invocation">
    Learn how to invoke tools
  </Card>

  <Card title="Authentication" icon="key" href="/mcp/capabilities/authentication">
    Understand authentication requirements
  </Card>
</CardGroup>