Switch MCP tool names from underscore to hyphen separator

[jpoehnelt]

Problem

MCP tool names use underscores as separators: drive_files_list. This is ambiguous when services or resources contain underscores (e.g., admin_reports_activities_list — is admin or admin_reports the service?). Additionally, tools/list used Discovery doc names while tools/call validated against configured aliases (#162).

MCP Spec Constraints

• Max 64 characters
• Must start with a letter
• Only lowercase letters and hyphens allowed
• Dots are NOT allowed per spec
• Underscores are used in ecosystem but not mandated

Proposal

Switch from underscore to hyphen as the hierarchy separator:

Before:  drive_files_list              (ambiguous with split("_"))
After:   drive-files-list              (unambiguous with split("-"))

Hyphens are safe because Google API service/resource names contain underscores and dots but never hyphens, so - is an unambiguous separator. Parsing becomes tool_name.splitn(3, "-").

Changes required

1. build_tools_list — join service, resource, method with - instead of _
2. handle_tools_call — split on - instead of _
3. Use configured service alias (not Discovery doc name) as prefix
4. Update compact mode tool naming to match

Breaking change

This changes all MCP tool names. Since the MCP ecosystem is early and tool names are dynamically discovered via tools/list, this should be transparent to well-behaved clients.

Consolidates

• Fixes MCP tools/list returns uncallable tool names for aliased services (events, apps-script, admin-reports) #162 (uncallable tool names for aliases)
• Fixes MCP Server Tool Name Parsing Breaks on Multi-Word Resource Names #170 (parsing breaks on multi-word resources)
• Supersedes PR fix: use service alias in MCP tool names for aliased services #224 and PR fix(mcp): align tools/list namespace with aliased services #165