OPNSense MCP Server

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the tool 'gets' details, implying a read-only operation, but doesn't clarify if it requires authentication, has rate limits, returns structured data, or handles errors. The description is minimal and misses key behavioral traits needed for safe and effective use in an unannotated context.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, efficient sentence with no wasted words. It's front-loaded with the core action and resource, making it easy to parse. However, it's overly concise to the point of under-specification, lacking necessary details for a tool with no annotations or output schema, which slightly reduces its effectiveness.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the complexity (a read operation with a required parameter), lack of annotations, and no output schema, the description is incomplete. It doesn't explain what details are returned, error conditions, or behavioral constraints. For a tool that likely returns structured firewall rule data, this leaves significant gaps for an AI agent to operate effectively.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema has 100% description coverage, with the 'uuid' parameter clearly documented as 'Firewall rule UUID'. The description adds no additional meaning beyond what the schema provides (e.g., no format examples or context about UUID sourcing). With high schema coverage, the baseline score of 3 is appropriate, as the description doesn't compensate but also doesn't detract.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description 'Get firewall rule details' clearly states the action (get) and resource (firewall rule), but it's vague about what 'details' includes. It distinguishes from siblings like 'list_firewall_rules' (which likely returns multiple rules) by focusing on a single rule, but doesn't explicitly differentiate from 'find_firewall_rules' (which might search). The purpose is understandable but lacks specificity about the scope of details returned.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., needing a UUID), exclusions, or compare to siblings like 'list_firewall_rules' (for bulk retrieval) or 'find_firewall_rules' (for searching). Usage is implied only by the tool name, leaving the agent to infer context without explicit direction.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.