OPNSense MCP Server

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

No annotations are provided, so the description carries full burden. It states 'Get' which implies a read-only operation, but doesn't disclose behavioral traits like whether it requires authentication, what happens if the VLAN doesn't exist (e.g., error handling), or the format of returned details. This leaves significant gaps for a tool with no annotation coverage.

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 extremely concise with just three words, which is efficient for a simple tool. However, it's arguably too brief—it could benefit from slightly more context without becoming verbose. The structure is front-loaded but minimal.

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 no annotations and no output schema, the description is incomplete. It doesn't explain what 'details' includes (e.g., configuration, status), error conditions, or return format. For a tool with one required parameter and no structured output documentation, this leaves the agent with insufficient context to use it 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?

Schema description coverage is 100%, with the single parameter 'tag' documented as 'VLAN tag number'. The description doesn't add any meaning beyond this, such as format constraints (e.g., numeric range) or examples. Baseline 3 is appropriate since the schema already fully describes the parameter.

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 VLAN details' clearly states the action (get) and resource (VLAN details), which is better than a tautology. However, it's somewhat vague about what 'details' encompasses and doesn't differentiate from sibling tools like 'list_vlans' or 'find_devices_on_vlan' that also retrieve VLAN-related information.

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?

No guidance is provided on when to use this tool versus alternatives. With siblings like 'list_vlans' (likely returns all VLANs) and 'find_devices_on_vlan' (returns devices on a VLAN), the description doesn't clarify that this tool retrieves configuration details for a specific VLAN identified by tag.

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