opn_add_firewall_category

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

With no annotations, the description notes that 'creating one does not affect traffic or rules,' providing safety context. It also states the return type, but lacks details on error conditions or idempotency.

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?

Concise with clear sections: purpose, usage guide, parameter list, return info. Every sentence adds value with no redundancy.

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 simple parameter set (2 params, no nested objects) and presence of output schema, the description fully covers what the tool does, its parameters, and what it returns.

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?

Adds constraints not in schema: name length (1-255 chars), no commas, and color format (hex without '#') with example and default. Schema coverage is 0%, so this is valuable.

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?

Clearly states 'Create a new firewall rule category' as a specific verb+resource. Distinguishes from siblings like opn_add_firewall_rule by emphasizing categories are metadata and do not affect traffic.

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?

Explicitly says 'Use this when you need to create a category for organizing firewall rules.' While it doesn't mention when not to use, the context makes it clear for category creation vs. rule creation.

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