Jira MCP has 19 well-named tools with complete input schemas and descriptions. Naming follows verb_noun convention (jira_search, jira_create_issue, jira_update_issue). All tools have descriptions (avg ~80 chars, within baseline 34-392). Input schemas are properly typed with required fields declared. However, parameter descriptions are sparse or missing context: 'assignee_id' lacks guidance on how to obtain an Atlassian account ID; 'status' in jira_transition lacks enum values or valid options; output schemas are undocumented (LLMs cannot predict response structure); error handling is generic ('Error: {type}: {e}') with no recovery guidance; no tool annotations (readOnlyHint, destructiveHint) despite clear risk levels (READ_ONLY, WRITE, DESTRUCTIVE). Composition is sound, each tool has one responsibility, and naming disambiguates similar operations (jira_list_comments vs jira_add_comment). Defaults are safe (max_results=20, priority='Medium'). Missing: parameter constraints (enums for status, priority, issue_type), output schema documentation, and actionable error messages.

• Add output schema documentation to every tool. Example for jira_get_issue: 'Returns {key: string, summary: string, status: string, assignee: {id: string, email: string}, created: ISO8601, updated: ISO8601, description: string}'. This enables LLMs to plan downstream calls.
• Replace free-form parameter descriptions with enums and constraints. For jira_transition, add 'status': {type: 'string', enum: ['To Do', 'In Progress', 'In Review', 'Done'], description: 'Target status. Call jira_get_transitions(issue_key) first to see available options.'}
• Implement actionable error messages. Instead of 'Error: ValueError: invalid status', return 'Invalid status: got "pending", must be one of: To Do, In Progress, In Review, Done. Call jira_get_transitions(issue_key) to see available transitions.'
• Add tool annotations to schema. For destructive tools (jira_delete_comment, jira_delete_attachment), add 'destructiveHint': true. For read-only tools, add 'readOnlyHint': true. This enables agents to reason about safety.
• Document pagination for list tools. Add 'offset' and 'limit' parameters to jira_search, jira_list_comments, jira_list_attachments, jira_list_users. Return 'total_count' and 'has_more' in responses. Cap default limit at 20-50 items.