APCore MCP exposes a single tool __apcore_approval_check with a clear, functional design. The tool has a well-defined input schema, explicit parameter descriptions, and structured output documentation in the description. However, the tool name violates verb-noun conventions (starts with underscore and uses 'check' instead of a more specific action verb like 'poll_approval' or 'get_approval_status'), and there are no parameter constraints (enums, min/max) defined. The description is adequate (116 chars) but lacks actionable recovery guidance beyond the basic workflow. The tool is narrowly scoped (approval polling only), which is appropriate for a bridge pattern, but the server overall offers limited functionality, this is a specialized integration tool rather than a general-purpose MCP server. The implementation is clean and secure (no secrets in parameters), but the naming and parameter validation fall short of production-grade baselines.

• Rename tool from '__apcore_approval_check' to 'poll_approval_status' or 'get_approval_status' to follow verb-noun convention and remove non-standard underscore prefix.
• Add JSON Schema constraints to approval_id parameter: if it is a UUID, declare format: 'uuid'; if alphanumeric with fixed length, add minLength/maxLength and pattern constraints.
• Expand tool description to include error cases: 'If status is "rejected", the approval cannot be retried. If approval_id is invalid, returns 404, verify the id from the APPROVAL_PENDING response. If the service times out, retry after waiting (exponential backoff recommended).'
• Document the complete output schema as a structured response type or return value specification, not just in prose. Specify field types, whether fields are nullable, and what each status value means (pending → still waiting, approved → retry with _meta.approvalId, rejected → operation failed).
• Consider adding a 'timeout_seconds' or 'retry_count' parameter if the client needs control over polling behavior, with defaults that suit common approval latencies (e.g., 30-second timeout).