Overview

This PR implements dynamic tool protocol resolution that properly respects the precedence hierarchy: Support > Preference > Defaults.

Precedence Hierarchy

The tool protocol is now resolved in the following order:

1. User Preference - Per-Profile (explicit profile toolProtocol setting) - highest priority
2. User Preference - Global (VSCode setting when set to "native") - user override
3. Model Default (defaultToolProtocol in ModelInfo) - model-specific preference
4. Provider Default (configurable list, XML for others) - provider fallback
5. XML Fallback (final fallback when nothing else is specified)
6. Support Validation (if native chosen but model doesn't support it, fall back to XML)

Key Changes

Type Definitions

• Added defaultToolProtocol field to ModelInfo type
• Added toolProtocol field to ProviderSettings type
• Created rooModelDefaults configuration object for Roo provider

Core Resolution Logic

• Created resolveToolProtocol() utility function that centralizes all resolution logic
• Handles support validation to prevent using native tools with unsupported models
• Global VSCode setting only applies when explicitly set to "native" (non-default)

Integration Points Updated

• Task.ts: Constructor, getSystemPrompt, attemptApiRequest, error messages (9 locations)
• System prompt generation for preview
• Tool result formatting
• All tool execution points

Bug Fixes

• Error messages now show correct tool usage guidelines (XML vs native) based on resolved protocol
• Roo provider model defaults now properly merged in system prompt preview
• All test mocks updated to include required apiConfiguration property

Testing

• 33 comprehensive tests for resolveToolProtocol covering all scenarios
• All 4,161 tests pass across all test suites
• Updated snapshots for system prompt tests
• Fixed test mocks for multiApplyDiffTool, readFileTool, and applyDiffTool.experiment

Configuration Example

Roo Model Defaults

export const rooModelDefaults: Record<string, Partial<ModelInfo>> = {
  "minimax/minimax-m2:free": {
    defaultToolProtocol: "native",
  },
}

Provider Defaults

Currently all providers default to XML (empty list in getProviderDefaultProtocol()). To add native-preferred providers:

function getProviderDefaultProtocol(provider: ProviderName): ToolProtocol {
  const nativeProviders: ProviderName[] = [] // Add providers here
  return nativeProviders.includes(provider) ? TOOL_PROTOCOL.NATIVE : TOOL_PROTOCOL.XML
}

What This Enables

• Models can specify their preferred tool protocol via defaultToolProtocol
• Users can override with global VSCode setting (when set to "native")
• Per-profile settings (future) will take highest priority
• Proper fallback chain ensures XML is used when native isn't supported
• Error messages always show correct guidelines for the resolved protocol