Reddit User MCP has 9 tools with consistent naming (verb_noun pattern) and basic schemas. All tools have descriptions and input parameters with types. However, descriptions are generic (avg ~60 chars, well below the 194-char baseline), lack actionable context for LLM selection, and omit critical details like prerequisites, return structures, and error recovery guidance. Output schemas are not documented, responses are JSON-stringified without field definitions. Parameters lack constraints (e.g., no enum for post sorting, no regex for IDs). Error handling is minimal: catch-all try/catch blocks return generic error text without recovery hints. No tool annotations (readOnlyHint/destructiveHint) despite clear read/write distinction. Composition is reasonable (single responsibility per tool), but chaining is weak, tools return opaque IDs without context for downstream calls.

• Expand tool descriptions to 100-200 chars. Include: what the tool does, when to use it (vs similar tools), what it returns, and any prerequisites. E.g., 'Fetch recent posts from a specific Reddit user. Use this to review a user's posting history; for subreddit-wide posts, use get_hot_posts. Returns post ID, title, score, and permalink.'
• Document output schemas explicitly. Define the structure of RedditPost and RedditComment objects with field types and descriptions. Return structured objects, not JSON strings. E.g., { posts: [{ id: string, title: string, score: number, ... }], total: number }
• Add tool annotations: set destructiveHint=true for hide_comment, reply_to_comment, post_comment. Set readOnlyHint=true for all get_* tools. This enables agents to reason about side effects.
• Improve error handling: catch specific error types (network, auth, validation), return categorized errors with recovery hints. E.g., 'User not found. Try search_users() with a partial name.' or 'Invalid post ID format. Expected alphanumeric string (e.g., abc123).'
• Add parameter constraints: postId and commentId should include regex pattern (e.g., /^[a-z0-9]+$/) and length limits. username should clarify format (no /u/ prefix). Add enum or pattern for subreddit names.