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 finds ARP entries by hostname pattern, implying a read-only search operation, but lacks details on permissions, rate limits, output format, or error handling. For a tool with no annotations, 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 is a single, efficient sentence that directly states the tool's purpose without unnecessary words. It is front-loaded and wastes no space, making it easy to understand at a glance.

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 the tool returns (e.g., list of entries, error messages), behavioral aspects like performance or limitations, or how it integrates with sibling tools. For a search tool in a network management context, more context is needed for effective use.

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 'pattern' parameter clearly documented as 'Hostname pattern to search'. The description adds minimal value by restating 'hostname pattern' but doesn't provide additional context like pattern syntax (e.g., wildcards) or examples. Baseline score of 3 is appropriate as the schema does the heavy lifting.

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 clearly states the action ('Find') and resource ('ARP entries'), specifying the search criterion ('by hostname pattern'). It distinguishes from siblings like 'find_arp_by_ip' and 'find_arp_by_mac' by indicating the search is based on hostname patterns, not IP or MAC addresses. However, it doesn't explicitly differentiate from 'list_arp_entries', which might list all entries without filtering.

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 explicit guidance on when to use this tool versus alternatives is provided. The description implies usage for searching ARP entries by hostname pattern, but it doesn't specify scenarios, prerequisites, or exclusions. For example, it doesn't clarify if this is for real-time queries or historical data, or how it compares to 'list_arp_entries' for broader searches.

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