Support qualified tool names in user tool sets

[Copilot]

Description

User tool sets (*.toolsets.jsonc) resolved tools entries only by unqualified reference name. Tools referenced in prompts/chat-modes by qualified names — vscode/memory, github/*, execute/runInTerminal — never matched, so MCP (github, azure) and built-in tool-set members were silently dropped.

{
  "CurrentTools": {
    "tools": ["vscode/memory", "execute/runInTerminal", "read/readFile", "github/*"],
    "description": "Slim tools",
    "icon": "tools"
  }
}

Resolution now flows through full reference names, which is how tools are referenced everywhere else.

Changes

• Member resolution (toolSetsContribution.ts): resolve each tools entry via getToolByFullReferenceName first — handles qualified names and their unqualified aliases — then fall back to the legacy getToolByName/getToolSetByName lookups for backward compatibility.
• Schema completions: build the JSON schema enum from qualified full reference names (getFullReferenceName) so autocomplete in the toolsets file matches prompt referencing.
• Interface: widen getFullReferenceName to accept IToolData | IToolSet (implementation already supported it); update the mock accordingly.
• Test: cover qualified-name round-tripping for tools and tool sets in languageModelToolsService.test.ts.

[jamesmontemagno]

Tested and working for me here

[Copilot]

Pull request overview

This PR fixes user tool sets (*.toolsets.jsonc) dropping tools/tool sets referenced via qualified “full reference names” by switching resolution and schema completions to use ILanguageModelToolsService.getToolByFullReferenceName(...) / getFullReferenceName(...), aligning tool set configuration with prompt/tool referencing semantics.

Changes:

• Update tool set member resolution to prefer full-reference-name lookup (qualified + aliases), with legacy unqualified fallback.
• Update the toolsets JSON schema enum values to emit full reference names for tools and tool sets.
• Widen getFullReferenceName(...) to accept IToolData | IToolSet, and add a round-trip test for qualified names.

Show a summary per file

File	Description
src/vs/workbench/contrib/chat/test/common/tools/mockLanguageModelToolsService.ts	Updates mock interface signature for getFullReferenceName to accept tools and tool sets.
src/vs/workbench/contrib/chat/test/browser/tools/languageModelToolsService.test.ts	Adds test coverage for qualified full-reference-name round-tripping for tools and tool sets.
src/vs/workbench/contrib/chat/common/tools/languageModelToolsService.ts	Widens the ILanguageModelToolsService.getFullReferenceName interface signature to include IToolSet.
src/vs/workbench/contrib/chat/browser/tools/toolSetsContribution.ts	Uses full reference names in schema completions and resolves tool set members via full reference name first, with legacy fallback.

Copilot's findings

• Files reviewed: 4/4 changed files
• Comments generated: 0