feat: adding correct tool annotations

[vanhtuan0409]

Summary

• Add MCP ToolAnnotations with readOnlyHint to all registered tools
• list_databases, list_tables, and run_chdb_select_query are marked as readOnlyHint=True (always read-only)
• run_query annotation is set dynamically based on CLICKHOUSE_ALLOW_WRITE_ACCESS: read-only by default, non-read-only when write access is enabled

Motivation

MCP clients (e.g. Claude Code, ChatGPT) use tool annotations to decide whether to prompt users for confirmation before executing a tool call. Without annotations, clients may conservatively require confirmation for every call — even read-only ones like listing databases or tables.

Test plan

• Verify list_databases, list_tables, run_chdb_select_query expose readOnlyHint=true in tool metadata
• Verify run_query exposes readOnlyHint=true when CLICKHOUSE_ALLOW_WRITE_ACCESS is unset or false
• Verify run_query exposes readOnlyHint=false when CLICKHOUSE_ALLOW_WRITE_ACCESS=true

🤖 Generated with Claude Code

[CLAassistant]

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