Server defines 8 tools with complete input schemas and descriptions in Korean. Naming follows verb_noun pattern (slack_list_channels, slack_post_message, etc.). However, descriptions lack depth, most are 50-100 chars, below the 194-char baseline for production tools. No output schemas documented. Parameters have types and descriptions, but lack constraints (enums, ranges, patterns). No error handling guidance. Missing idempotency hints for write operations. Tool composition is sound (single responsibility), but descriptions don't explain WHEN to use each tool or dependencies between them.

• Add output schemas for all tools. Document the structure of Slack API responses (e.g., slack_list_channels returns {ok: boolean, channels: [{id, name, is_archived, ...}], response_metadata: {next_cursor}}). This enables LLMs to extract channel_id for downstream calls.
• Expand descriptions to 150-250 chars. Include WHEN to use each tool and dependencies. E.g., 'Fetch recent messages from a channel. Call slack_list_channels first to get valid channel_id. Returns up to 10 messages by default; use limit parameter to adjust.'
• Add numeric constraints to schema. Set minimum: 1, maximum: 200 for limit parameters. Add pattern validation for timestamp fields (format: '1234567890.123456'). Add enum for reaction parameter or document valid Slack emoji names.
• Implement error recovery guidance. Wrap Slack API responses with actionable error messages. E.g., if channel_id is invalid, return 'Channel not found. Call slack_list_channels to see available channels.' instead of raw Slack error.
• Add idempotency hints to write operations. Document that slack_post_message is idempotent if called with identical channel_id and text within a short window. Offer optional idempotency_key parameter to prevent duplicates on retry.