update_dynamic_dns

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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=false, and openWorldHint=true, so the safety profile is covered. The description adds real behavioral context beyond them: that use_request_ip mode relies on the server's egress IP and therefore cannot verify the intended client IP.

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?

Two tight sentences with the core verb leading and the caveat following. Minor formatting noise (an unclosed leading quote) but no wasted content.

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?

With annotations covering safety and an output schema covering return values, the description only needs to resolve behavior and the required conditional, which it does. Fully documenting the 0%-coverage parameters would make it complete.

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 0%, so the description must carry the load. It does explain the ips/use_request_ip conditional and characterizes hostnames as fully qualified, but leaves the remaining semantics (list sizes, ip list format, hostname/IP pairing) undocumented.

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 a specific verb+resource ('Preview DDNS for fully qualified hostnames'), which importantly clarifies that despite the 'update_dynamic_dns' name this is a read-only preview operation. It does not explicitly distinguish itself from the update_dns_record/update_forward siblings that would otherwise seem related.

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 explains a conditional: omitting IPs requires use_request_ip=true, and warns that this mode cannot verify the intended client IP. However, there is no guidance on when to choose this preview tool over the actual update tools or plan_dns_batch/plan_dns_batch-style siblings.

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