opn_add_nat_rule

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

It discloses the savepoint protection mechanism, including the version-specific behavior (auto-revert on <26.7, immediate on 26.7+), and warns about the risk of lockout if not handled properly.

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 relatively concise but contains redundant warnings about the savepoint behavior, repeating information in multiple sentences. It could be streamlined, but remains clear and structured.

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?

The description gives enough context for the tool's purpose and key behaviors, but it does not mention the return value (though output schema exists) or any prerequisites. It does cover the main warning about savepoint and lockout. Overall, it is adequate but could be enhanced with parameter explanations.

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?

The description does not explain the meaning of any of the parameters (protocol, interface, target_ip, description, target_port, destination_port). It only refers to 'external port' and 'internal host' without linking to specific parameter names, leaving the parameter semantics unclear.

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 that the tool creates a NAT port forwarding rule and explains the use case: forwarding an external port to an internal host. This distinguishes it from general firewall rules and aligns with its name.

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?

It explicitly says 'Use this when you need to forward an external port to an internal host' and provides important caveats about savepoint behavior and steps to check opn_mcp_info and take backup if needed.

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