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. While 'Delete' implies a destructive mutation, the description doesn't specify whether this action is reversible, what permissions are required, whether it affects associated resources (e.g., frontends), or what happens on success/failure. For a destructive tool with zero annotation coverage, this is inadequate.

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 gets straight to the point with zero wasted words. It's appropriately sized for a simple delete operation and front-loads the essential information. Every word earns its place.

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 destructive mutation tool with no annotations and no output schema, the description is insufficient. It doesn't cover behavioral aspects like irreversibility, error conditions, or system impact. Given the complexity of deleting a critical HAProxy component and the lack of structured safety information, the description should provide more context about what 'delete' entails.

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 'uuid' clearly documented as 'Backend UUID'. The description doesn't add any meaning beyond what the schema provides—it doesn't explain how to obtain the UUID or what format it expects. With complete schema coverage, the baseline score of 3 is appropriate.

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 ('Delete') and resource ('HAProxy backend'), making the tool's purpose immediately understandable. It distinguishes itself from sibling tools like 'haproxy_backend_create' and 'haproxy_backend_list' by specifying the delete operation. However, it doesn't explicitly mention what constitutes a 'backend' or provide additional context about the resource being deleted.

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., needing the backend UUID from 'haproxy_backend_list'), consequences of deletion, or when not to use it (e.g., if the backend is currently in use). With multiple HAProxy-related siblings available, this lack of differentiation is a significant gap.

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