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

Annotations already declare readOnlyHint and openWorldHint, so the description's added value is real: it discloses that reverse lookups include forward verification, that avatar/description/url/social text records are returned, and that each call costs $0.005 USDC on Base via x402 — a payment/permission prerequisite no annotation covers. Left out are resolution chain/failure behavior and what happens if payment is not settled.

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?

A single front-loaded sentence that leads with the capability and directions, then the returned fields, then the price. It is dense and slightly run-on, but every clause carries information an agent needs before calling.

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?

With no output schema, the description correctly covers what comes back (address, verified primary name, text records) and adds the cost model. Minor ambiguity remains about which chain resolution runs against versus the Base payment chain, and about failure/empty-result behavior.

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% and the single parameter 'q' is already documented with examples in the schema, so the baseline is 3. The description reinforces the dual input mode (name or 0x address) and names the accepted name suffixes, but adds no format or validation detail beyond the schema.

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?

States a specific verb (resolve) with the exact resources (ENS and Basenames, with concrete TLD examples) and enumerates both directions: name → address and address → primary name, plus text records. An agent can immediately tell this apart from provisioning/DNS siblings like domain_dns or domain_whois.

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?

Usage is implied by the stated directions (forward lookup for a name, reverse lookup for a 0x address), so an agent can infer when to call it. But there is no explicit guidance on when to prefer this over siblings such as domain_dns or domain_whois, and no stated prerequisites for the paid x402 flow.

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