[FEATURE] lightweight MCP tool loading

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

when using MCP servers (e.g. home-assistant via ha-mcp), the full tool set loads at conversation start regardless of need. ha-mcp loads 92 tools at ~38k tokens.

many sessions only need a quick entity state check or a single service call. loading the full tool set for that is expensive and wasteful.

Proposed Solution

would be useful to support either:

a --tools filter on MCP load (e.g. only load ha_get_state, ha_search_entities)
a "light mode" profile that loads a curated subset
lazy tool loading — advertise tool names but defer schema loading until first use
this is partly an ha-mcp concern, partly a claude code MCP loader concern. flagging here since the token cost affects session budgets directly.

Alternative Solutions

_No response_

Priority

High - Significant impact on productivity

Feature Category

MCP server integration

Use Case Example

_No response_

Additional Context

_No response_