list_dns_domains

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the description does not need to restate safety. It adds the internal table reference but nothing about behavior beyond that (e.g., no mention of return format or pagination). The description is consistent with annotations, and given the annotations' coverage, the added value is minimal.

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 a single short sentence with no fluff. It immediately states the action and the resource, and the internal table reference is supplementary but relevant. It is appropriately concise.

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 list operation with no parameters and annotations covering the read-only nature, the description is sufficiently complete. It does not explain the output format, but without an output schema that is acceptable. The only minor gap is that it does not specify whether it returns all domains regardless of server, but that is likely implicit and not critical.

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 tool has zero parameters and the schema covers all properties (none). Since there are no parameters to explain, the description does not need to add parameter semantics. The baseline for 0 parameters is 4, and the description does not miss anything.

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 action (list) and the resource (all user domains). It also references the internal source table (pdns/list_domains), adding specificity. The name itself distinguishes it from sibling tools like list_dns_zones and list_dns_subdomains, so an agent can easily identify its purpose.

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 implies it is for listing domains, but it does not explicitly compare it to similar tools (e.g., list_dns_zones, list_dns_subdomains) or provide when-not-to-use guidance. The intended usage is clear from the name and context, but no explicit routing or exclusions are provided.

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