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

With no annotations, the description carries the full burden and does well: it discloses the transport (Cloudflare DoH over HTTPS), behavior (follows CNAME chains), timeout (5 s), and return shape (JSON array or error string). It misses rate limits or auth, but these are less critical for a public DoH query.

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?

Five sentences, every one adds value: purpose, usage positioning, behavioral details, return contract, and error handling. It is front-loaded with the core purpose and skips filler.

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?

The description is highly complete for a simple two-parameter tool, covering return values despite lacking an output schema, transport behavior, timeout, and alternatives. The one gap is the record-type contradiction with the schema, which creates a confusion risk that prevents a perfect score.

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%, which would normally give a baseline of 3, but the description lists SOA, CAA, and SRV as supported types while the schema enum only permits A, AAAA, MX, TXT, NS, and CNAME. This mismatch actively misleads the agent into providing values that will fail schema validation, reducing parameter clarity below baseline.

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 ('resolve') and resource ('single DNS record type'), and clearly distinguishes from sibling tools by positioning it as quick and targeted, explicitly contrasting with dossier_dns and dossier_full.

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?

Provides explicit when-to-use guidance ('Use for quick, targeted lookups of one record type') and names alternatives with reasons ('prefer dossier_dns for a full multi-type DNS audit in parallel, or dossier_full for a complete domain health check'), covering both usage and exclusions.

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