DNS Lookup

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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, and openWorldHint=true. The description adds behavioral context by specifying that the lookup is real-time and that ip_address input forces a specific record type restriction. No contradictions with 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 extremely concise—two short sentences. The first sentence defines the core action and supported types; the second covers usage constraints. No fluff, every word contributes meaning.

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 read-only, idempotent tool with no output schema, the description is fully adequate. It explains the input contract, supported record types, and conditional requirements. Nothing essential is missing.

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 already has 100% description coverage for all parameters. The description adds value by explaining the conditional logic between host_name and ip_address, and that ip_address forces record_types to ['all']. This goes beyond the schema's individual parameter descriptions.

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 retrieves real-time DNS records for a hostname or IP address. It enumerates supported record types (A, AAAA, MX, etc.) and explains the required condition when using ip_address. This distinguishes it well from sibling tools like dns_bulk_lookup (for multiple lookups) and dns_history (historical data).

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 gives explicit constraints: at least one of host_name or ip_address must be provided, and ip_address forces record_types to ['all']. However, it does not explicitly compare to sibling tools or provide when-not-to-use scenarios, which would elevate it to a 5.

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