opn_add_icmpv6_rules

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

With no annotations, the description fully carries the behavioral disclosure. It details the created rules, savepoint behavior on OPNsense <26.7 (auto-revert in 60s unless confirmed), and immediate application on 26.7+. It also warns about potential lockout and suggests mitigation, covering important side effects without contradicting any annotations.

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 well-structured and front-loaded with purpose and usage. It lists the 5 rules concisely, then notes version-specific behavior, parameters, and return type. Every sentence adds value; no fluff, and it's easy to scan.

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 tool that creates multiple rules with version-dependent behavior, the description is remarkably complete. It explains the rules created, version differences, confirmation process, and required pre-checks (savepoint_support and backups). The return format (revision, rules, instructions) is also specified, making the tool fully understandable without additional context.

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 coverage is 0%, so the description must compensate. It clarifies the sole parameter 'interface' with examples ('lan', 'opt1', 'opt2') and indicates default 'lan'. While minimal, it adds enough meaning for a simple parameter, though it could explicitly state it's the OPNsense interface name.

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 tool creates essential ICMPv6 firewall rules for IPv6 operation. It specifies the exact resource (ICMPv6 rules) and distinguishes from generic firewall rule tools by focusing on the mandatory ICMPv6 set (5 specific rules per RFC 4890).

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 setting up IPv6 on an interface' and explains why ICMPv6 is mandatory, providing strong context. It also gives operational guidance for different OPNsense versions, recommending checks via opn_mcp_info and backups via opn_download_config. This well differentiates from alternatives like opn_add_firewall_rule.

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