Add Exa search performance defaults injection for MCP tools

[gary149]

Summary

This PR adds support for injecting default Exa search parameters into MCP tool invocations, allowing configuration of search type and livecrawl behavior at the application level while respecting LLM-provided overrides.

Key Changes

• Added configuration options EXA_SEARCH_TYPE and EXA_LIVECRAWL to control Exa search defaults
• Implemented automatic parameter injection in executeToolCalls() that:
  • Detects when an Exa MCP server is being invoked
  • Injects configured defaults for type and livecrawl parameters
  • Only applies defaults when the LLM hasn't explicitly set these parameters
• Updated environment configuration with new Exa-specific settings (defaults: fast for search type, never for livecrawl)

Implementation Details

• The injection logic checks isExaMcpServer() to identify Exa MCP servers by URL
• Parameters are only set if they're undefined in the tool arguments, preserving any LLM-specified values
• Configuration values can be left empty to disable the override behavior
• Changes are minimal and focused, adding the feature without modifying existing tool execution flow

https://claude.ai/code/session_01ULoVUMgYs2EcmPBWAN8fYg