Add agentURI metadata schema example to ERC-8004 reference

## Summary
- ERC-8004 reference mentions agentURI must follow Agent Metadata Profile but provides no schema
- Developers had no way to construct a valid agentURI JSON without the schema

## Type of Change
- [x] Documentation improvement

## Changes Made
- Added Agent Metadata Profile JSON example with required fields: name, description, image, services
- Added link to ERC-8004 specification

## Testing
- [x] Schema matches ERC-8004 Agent Metadata Profile format

Author: mefai-dev

skills/bnbchain-mcp-skill/references/erc8004-tools-reference.md

@@ -60,3 +60,24 @@ Get the verified payment wallet address for an ERC-8004 agent (for x402 / agent
 | network | string | Network name or chain ID (optional; default `bsc`) |
 
 **Returns:** `agentId`, `agentWallet`, `network`.
+
+---
+
+### Agent Metadata Profile Example
+
+The `agentURI` must point to a JSON file with the following structure:
+
+```json
+{
+  "name": "My Agent",
+  "description": "Description of the agent's capabilities",
+  "image": "https://example.com/agent-avatar.png",
+  "services": [
+    {
+      "name": "Trading",
+      "description": "Automated trading service",
+      "url": "https://example.com/api"
+    }
+  ]
+}
+```