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. 'List all VLANs' implies a read-only operation but doesn't disclose behavioral traits like pagination, rate limits, authentication needs, or what 'all' entails (e.g., active only, includes system VLANs). For a tool with zero annotation coverage, this is a significant gap in transparency.

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 'List all VLANs' is a single, efficient sentence with zero waste. It's front-loaded and appropriately sized for a simple list operation, earning full marks for conciseness.

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 0 parameters and no output schema, the description is minimal but adequate for a basic list tool. However, with no annotations and no output details, it lacks completeness regarding behavioral context (e.g., return format, error handling). It meets the minimum viable threshold but has clear gaps.

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 tool has 0 parameters, and schema description coverage is 100%, so no parameter documentation is needed. The description doesn't add parameter semantics, but with no parameters, a baseline of 4 is appropriate as it doesn't mislead or omit required information.

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 'List all VLANs' clearly states the action (list) and resource (VLANs), making the purpose immediately understandable. It distinguishes from siblings like get_vlan (singular) and create_vlan/delete_vlan (mutations). However, it doesn't specify scope or format, keeping it from a perfect 5.

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 like get_vlan (for a specific VLAN) or find_devices_on_vlan (for VLAN details). It lacks context about prerequisites, such as whether VLANs must be configured first, or any exclusions.

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