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

With no annotations, the description carries the full burden. It clearly indicates a read-only lookup operation and mentions the DNS server context, but it does not disclose potential errors, timeouts, or the response format. The behavior is straightforward, yet lacks depth for a fully transparent picture.

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 two sentences long, front-loads the purpose, and lists the record types efficiently. Every word earns its place with no redundancy or fluff.

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?

Without an output schema, the description should explain the structure of returned results, but it only says 'returns results' without specifying format or shape. The tool has only two parameters and no side effects, yet the missing return details leave a notable gap for the agent.

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 input schema provides 100% coverage with descriptions for both 'domain' and 'server', including an enum and a default value. The tool description adds minimal semantic value beyond what the schema already states, so the baseline of 3 is appropriate.

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 uses a specific verb ('look up') and a resource ('all common DNS records') with a clear list of record types, which distinguishes it from sibling tools like dns_health or dns_propagation. It also specifies that results come from a designated DNS server, fully clarifying the tool's scope.

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 general usability for comprehensive DNS lookups but does not explicitly state when to use this tool versus alternatives like dns_record or dns_propagation. No exclusions or conditional guidance are provided, leaving the agent to infer the tool's place among siblings.

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