Server has 5 tools with basic verb-noun naming (get_*, check_*), but critical quality gaps undermine usability. All tools lack parameter descriptions, the rubric requires every parameter to have a description explaining what it controls. Tool descriptions are present but generic and lack actionable context (e.g., 'Get assignmets whose deadline will be witin the designated date' has a typo and doesn't explain when to use it vs. other tools). No output schemas are documented, LLMs cannot plan downstream calls or extract structured data. Error handling is minimal: most tools return plain strings or raise generic exceptions without recovery guidance. The 'days' parameter in get_due_assignments and get_pending_quizzes lacks type constraints (min/max), allowing LLMs to pass absurd values. No tool declares what it returns or how to chain results. Security: MOODLE_TOKEN is injected via environment variable (good), but no audit logging or permission gates exist.

• Add descriptions to all parameters. For 'days' in get_due_assignments: 'Number of days to look ahead for assignment deadlines (1 - 365). Defaults to 7 if omitted.'
• Document output schemas. E.g., get_due_assignments returns a list of objects with fields: course_name (string), assignment_name (string), due_date (ISO 8601 string). Use JSON Schema in the tool definition.
• Rewrite tool descriptions to be LLM-optimized (50 - 200 chars). Example: 'Fetch assignments due within N days. Use this to help students prioritize work. Returns course name, assignment name, and due date.'
• Add numeric constraints to 'days' parameter: minimum 1, maximum 365. Validate input and return 'Invalid days: must be 1 - 365' if violated.
• Enhance error messages with recovery hints. Instead of '課題情報の取得に失敗しました', return 'Failed to fetch assignments. Verify MOODLE_URL and MOODLE_TOKEN are set correctly. If the issue persists, contact your Moodle administrator.'