Server has 9 well-named tools with complete input schemas and descriptions. Naming follows verb_noun convention (list_, get_, post_, search_, add_). All tools have descriptions (avg 65 chars, within baseline 34-392). Input schemas are properly typed with required fields marked. However, output schemas are completely undocumented, LLMs cannot plan downstream calls or extract needed fields. Parameter descriptions lack constraints (e.g., no enum for reaction names, no format for timestamps). Error handling is absent from visible code. No pagination guidance in descriptions despite tools accepting limit/cursor. Missing security considerations for token injection via message text.

• Document output schemas for all 9 tools. Example for slack_list_channels: 'Returns {channels: [{id: string, name: string, is_archived: boolean}], response_metadata: {next_cursor: string}}'. This enables LLMs to chain calls and extract needed IDs.
• Add enum constraints to 'reaction' parameter in slack_add_reaction. Replace description with: 'The emoji reaction name (e.g., thumbsup, heart, laughing). See Slack emoji list for valid names.'
• Add min/max bounds to numeric parameters. E.g., 'limit': {type: 'number', minimum: 1, maximum: 200, default: 100}. Update descriptions to state these bounds.
• Wrap API errors with recovery guidance. E.g., if slack_post_message fails with 'channel_not_found', return: 'Channel not found. Call slack_list_channels() to find the correct channel_id, or verify the channel_id is in format C1234567890.'
• Add pagination guidance to tool descriptions. E.g., 'Use cursor from previous response to fetch next page. If response has no next_cursor, you have reached the end.'