Stdlib-first MCP tool-call security monitor and gateway with five-layer defense against prompt injection, PII exfiltration, shadow servers, and behavioral drift
Server defines 5 tools with basic schemas and descriptions, but exhibits significant quality gaps. Tool names lack action verbs (inspect_call, inspect_output are acceptable but generic). Descriptions are present but brief (50-100 chars), below the 194-char baseline for production tools. Input schemas exist but lack parameter-level descriptions, the 'arguments' parameter in inspect_call is typed as 'object' with no field-level schema. Output schemas are completely undocumented. Error handling is absent from tool definitions. No evidence of pagination, result limits, or recovery guidance. The health/ready/metrics tools are operational probes, not domain tools, and dilute the security-focused toolset.
Health check endpoint for the MCP Security Gateway Monitor
Inspect and evaluate MCP tool calls through a five-layer defense system for security threats including prompt injection, PII exfiltration, shadow servers, and behavioral drift
Inspect tool output for data exfiltration, PII leakage, and other security violations
Metrics endpoint exposing security gateway performance and detection statistics
Readiness probe endpoint for the MCP Security Gateway Monitor
Input schemas lack parameter-level descriptions and type constraints. 'arguments' in inspect_call is typed as bare 'object' with no field documentation, forcing LLMs to guess structure.
No output schemas documented. LLMs cannot predict what inspect_call or inspect_output return, preventing downstream tool chaining and forcing exploratory calls.
Tool descriptions are 40-100 characters, well below the 194-char production baseline. 'Inspect and evaluate MCP tool calls...' lacks WHEN to use, prerequisites, and what the verdict means.
No error handling guidance. If inspect_call detects a threat, what does the LLM do? Block the call? Escalate? Retry? No recovery path is documented.
Inferred effective spec: <=2025-11-25.
| Scored | Grade | Overall | Spec posture | Rubric |
|---|---|---|---|---|
| 2026-09-23 | D | 54 | <=2025-11-25 | v2 |
health, ready, and metrics are operational probes, not domain tools. They clutter the tool namespace and distract from the core security inspection mission. Move to a separate /health endpoint.