mcp-opnsense

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

With no annotations provided, the description carries full burden but only states it's a registration action and mentions a required follow-up step. It doesn't disclose critical behavioral traits like whether this is a write operation (implied but not stated), permission requirements, rate limits, error conditions, or what happens if an account already exists. For a mutation tool with zero annotation coverage, this is insufficient.

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 perfectly concise with two sentences that each serve distinct purposes: the first states the core functionality, the second provides critical usage guidance. There's zero wasted language, and the most important information (what the tool does) is front-loaded.

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 mutation tool with no annotations and no output schema, the description is minimally adequate. It states the purpose and provides one important behavioral note (need to run apply afterwards), but lacks information about return values, error handling, side effects, or system state changes. The 100% schema coverage helps, but behavioral context remains sparse.

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 fully documents all three parameters with descriptions and enum values. The description adds no additional parameter information beyond what's in the schema, but doesn't need to since schema coverage is complete. This meets the baseline expectation.

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 specific action ('Register a new ACME account') with the target resource ('with a certificate authority'), and distinguishes it from siblings like 'opnsense_acme_register_account' by specifying it's for adding an account rather than just registering. The mention of specific CAs (Let's Encrypt, ZeroSSL) adds concrete examples.

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 clear context by stating 'Run opnsense_acme_apply afterwards,' which gives important sequencing guidance. However, it doesn't explicitly differentiate when to use this versus the similar 'opnsense_acme_register_account' sibling tool, nor does it mention prerequisites or when-not-to-use scenarios.

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