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 the action ('Find') but doesn't disclose behavioral traits such as whether this is a read-only operation, what permissions are required, if it's cached or real-time, rate limits, or what happens on no matches. The description is minimal and lacks critical operational context for a tool that likely queries network data.

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 zero waste. It's front-loaded with the core purpose and uses clear, direct language. Every word earns its place, making it easy to parse quickly without unnecessary elaboration.

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 for a tool that queries network data. It doesn't explain what the return values are (e.g., list of ARP entries, error handling), behavioral aspects like read-only nature, or performance implications. For a tool with potential complexity in network environments, this leaves significant gaps for an AI agent.

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 parameter 'ipPattern' well-documented in the schema (e.g., accepts IP address, prefix, or subnet). The description adds no additional parameter semantics beyond what's in the schema, such as format examples or edge cases. With high schema coverage, the 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 verb ('Find') and resource ('ARP entries') with the specific mechanism ('by IP address or subnet'). It distinguishes from sibling tools like 'find_arp_by_hostname' and 'list_arp_entries' by specifying the lookup method, though it doesn't explicitly contrast them. The purpose is unambiguous but lacks explicit sibling differentiation.

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 like 'find_arp_by_hostname', 'find_arp_by_mac', or 'list_arp_entries'. The description implies usage for IP-based ARP lookups but offers no context about prerequisites, performance considerations, or exclusions. This leaves the agent to infer usage from the name alone.

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