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

Annotations already cover read-only/idempotent/open-world/non-destructive, yet the description adds genuinely new behavior: ENS is returned only when it resolves back to the address (reverse-resolution constraint), both values are self-declared by the owner, and the tool never links a wallet to a private person. That provenance and validity framing goes well beyond the structured fields.

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?

Front-loaded with the triggering condition, then the parameter, then the return shape, then the boundaries. Every sentence earns its place and the ordering matches how an agent needs the information.

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 an output schema present the return values need not be detailed, and the description still supplies the resolution semantics, the self-declared caveat, and both boundaries (no name search, no private-person linkage). Nothing an agent needs to call this correctly 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?

Schema description coverage is 100% and the single parameter's description ('0x... on an EVM chain, or a Solana address') is fully documented in the schema. The description's 'Pass address (0x or Solana)' merely repeats it, so baseline 3 applies with no added syntax 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+resource (resolve a wallet address to its public name) and names the concrete outputs (ENS primary name, Farcaster verified account). An agent can tell exactly what this tool yields and that it is unrelated to the sibling feedback/screening tools.

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?

Explicitly triggers on 'the user asks whether a wallet address has a public name' and adds clear exclusions: 'It cannot search by a person's name' and 'never links a wallet to a private person.' This is a full when/when-not statement, not just implied context.

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