Configure Safe Firewall (UFW)

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

Annotations already indicate destructive and idempotent behavior. The description adds value by revealing the crucial safety check for OpenSSH before enabling the firewall, which is beyond what annotations provide. It does not contradict annotations. The description could further detail whether existing rules are preserved or overwritten.

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 extremely concise: two sentences that communicate the core purpose and the most critical safety information. No unnecessary words or repetition. The safety note is appropriately emphasized.

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 tool with no output schema and no nested objects, the description covers the main action and safety but lacks information on return values or success/failure indication. The idempotent hint and destructive hint help, but the description could state what happens when executed (e.g., 'Enables UFW after applying allowed rules').

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 baseline is 3. The description does not add new meaning beyond what the schema already provides for 'allow_nginx' and 'custom_ports'. It mentions the safety check for port 22, but that is not directly related to parameter semantics.

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 states the tool configures UFW firewall rules safely, which clearly identifies the verb (configures) and resource (UFW firewall rules). It distinguishes from sibling tools like 'secure_env_writer' or 'setup_nginx_reverse_proxy' by focusing on firewall configuration. However, it could be more specific about the exact action (e.g., enabling the firewall after adding rules).

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 highlights a critical safety guideline: always verifying OpenSSH is allowed before enabling the firewall to prevent lockout. However, it does not explicitly state when to use this tool versus alternatives (e.g., for initial firewall setup or adding rules). The guidance is present but limited to safety context.

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