dns-lookup

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

Without annotations, the description carries the full transparency burden. It discloses the use of Cloudflare DoH, specific record types, and special TXT extraction for SPF/DMARC/DKIM. It does not mention rate limits or auth, but the tool is read-only and non-destructive, so the behavior is well-covered.

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 three short sentences: core function, supported types with special note, and use cases. No redundant or irrelevant information. Front-loaded with the essential verb and resource.

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 2-parameter tool with full schema coverage and no output schema, the description is complete. It explains input, special behavior for TXT, and practical applications. An agent has enough information to select and invoke this tool correctly.

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 100%, but the description adds significant value: it enumerates supported record types, explains that 'ALL' queries multiple types in parallel, and highlights TXT-specific extraction. This contextual information aids the agent beyond the schema's basic field 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 specifies the tool's action ('DNS record lookup'), resource ('any domain'), and method ('via Cloudflare DoH'). It lists supported record types, distinguishing it from sibling tools like domain-whois or ssl-cert that handle different domain 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 explicitly states use cases: domain audits, email configuration verification, CDN setup checks, and infrastructure reconnaissance. It does not provide when-not-to-use or alternatives, but the listed contexts are clear enough for an agent to determine appropriate scenarios.

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