OPNSense MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure but offers minimal information. It states 'Create' which implies a write/mutation operation, but doesn't describe permissions required, whether the operation is idempotent, what happens on failure, or how the certificate integrates with HAProxy (e.g., if it becomes immediately active). The description lacks crucial behavioral context for a creation tool.

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, focused sentence with zero wasted words. It's appropriately sized for a tool with comprehensive schema documentation and gets straight to the point without unnecessary elaboration or repetition.

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?

For a certificate creation tool with 7 parameters, no annotations, and no output schema, the description is insufficient. It doesn't explain what the tool returns (e.g., success confirmation, certificate ID), error conditions, or how the created certificate is used in HAProxy. The combination of mutation behavior and missing output information creates significant gaps for agent understanding.

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%, so the schema already documents all 7 parameters thoroughly with descriptions and an enum for 'type'. The description adds no parameter-specific information beyond what's in the schema, not explaining relationships between parameters (e.g., how 'type' affects which other parameters are relevant) or providing usage examples. This meets the baseline for high schema coverage.

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 ('Create') and resource ('a certificate for HAProxy'), making the purpose unambiguous. It distinguishes from sibling tools like 'haproxy_certificate_list' by specifying creation rather than listing. However, it doesn't explicitly differentiate from other certificate-related tools that might exist in broader contexts.

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., when certificates are needed in HAProxy configuration), compare to other certificate management methods, or specify scenarios where creation is appropriate versus listing existing certificates with 'haproxy_certificate_list'.

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