antigravity-custom-tools-dart

name	antigravity-custom-tools-dart
description	Define stateless/stateful custom tools, validate JSON parameter schemas, or bridge MCP servers in Dart.

Dart Custom Tools & MCP Integration

Development workflow for exposing custom tools to a Google Antigravity SDK agent and bridging Model Context Protocol (MCP) servers.

1. Custom Tool Execution Steps

1. Schema Specification: Declare parameter maps with standard JSON schema keys (type, properties, required).
2. Defensive Extraction & Correlation: Validate incoming arguments explicitly, track callId correlation IDs across turns, and handle missing optional keys gracefully.
3. Self-Correcting Error Handling & Supplemental Media: Wrap execution in a try-catch block to return descriptive stringified errors or MediaContent assets (images, audio, files) directly in tool responses.

For detailed implementations, read references/tool_examples.md.

2. Model Context Protocol (MCP) Integration

• Configure McpServerConfig instances inside LocalAgentConfig(mcpServers: [...]).
• On session startup, McpBridge queries active server tools and dynamically constructs native Tool instances.

For complete MCP setup code, consult references/tool_examples.md.

Completion Criteria

• Tool parameters map accurately to JSON schemas with explicit required field declarations.
• Tool handlers wrap execution in try-catch blocks returning ToolExecutionException metadata or stringified error messages on failure.
• Supplemental media outputs attach valid MediaContent buffers (bytes, mimeType).
• McpServerConfig executable paths and environment variables are verified prior to launch.