Rails-native MCP server that exposes database queries, background jobs, feature flags, rake tasks, cache operations, and custom tools as MCP tools
Single tool 'db.query' has a basic schema with type and enum constraints, but critical gaps undermine production readiness. Description is minimal (18 chars, well below 50-200 char baseline for A+ tools). No parameter descriptions visible in the schema, LLMs cannot infer what 'sql' or 'format' control. Output schema is undocumented. No error handling guidance, no recovery paths, no mention of SQL injection risk or permission gates. The tool exposes raw database access without visible input validation, sanitization, or audit context despite the codebase showing audit_logger infrastructure. Tool composition is monolithic (one tool for all queries) rather than split by intent (read vs write, discovery vs mutation).
Run a SQL query.
Parameter descriptions missing. 'sql' and 'format' parameters have no descriptions explaining what they control, expected format, or constraints. LLMs cannot infer parameter meaning from names alone.
Tool description is 18 characters ('Run a SQL query.'), far below the 50-200 char baseline for A+ tools. Lacks WHEN to use it, WHAT it returns, and prerequisites. Does not state whether it modifies state or is read-only.
Output schema undocumented. No visible specification of what fields the response contains, their types, or structure. LLMs cannot plan downstream calls or extract data without knowing the response shape.
No error handling guidance. Tool provides no recovery hints, error classification, or actionable messages. A SQL syntax error or permission denial returns nothing the LLM can act on.
Inferred effective spec: <=2025-11-25.
| Scored | Grade | Overall | Spec posture | Rubric |
|---|---|---|---|---|
| 2026-09-23 | F | 41 | <=2025-11-25 | v2 |
SQL injection risk not addressed. Tool accepts raw 'sql' parameter with no visible input validation, sanitization, or parameterized query enforcement. Codebase shows audit_logger but no injection guards in tool definition.