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

Goes well beyond the readOnlyHint/openWorldHint annotations by disclosing the paid x402 cost ($0.001), the no-charge-on-404 policy, and that address-direction results are verified to resolve back to the same address. These are exactly the operational details an agent needs before committing a paid call.

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?

Dense and front-loaded, leading with the dual direction of resolution before enumerating cost and edge cases. The parenthetical list of profile records is somewhat long but conveys concrete return fields, so it largely earns its space.

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 carries the burden of explaining return values and does so thoroughly for both directions, plus cost and error semantics. An agent has everything needed to call it correctly and interpret results.

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%, so the baseline is 3, but the description adds meaning by mapping each parameter to a distinct output shape (name -> address + profile records + primary-name flag; address -> primary ENS + primary Basename). It also reinforces the mutual exclusivity of the two parameters.

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) and resource (ENS names and Basenames) with the bidirectional scope spelled out, including the exact outputs for each direction. It is immediately distinguishable from siblings like domain_intel or wallet_report.

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?

Clearly defines applicable inputs (.eth, *.base.eth, subnames, offchain/CCIP-Read) and the failure condition (unknown = 404, not charged), which gives an agent strong context for when the tool applies. It stops short of naming an alternative sibling or an explicit when-not-to-use-this-tool rule.

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