lookup_agent

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

With no annotations provided, the description carries the full behavioral disclosure burden and does so thoroughly. It states the operation is read-only and on-chain only, clarifies that the wallet does not fetch the website, enumerates the returned fields, and prominently warns about the trust implications of permissionless registration and feedback. This exceeds typical descriptions in transparency.

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 long but front-loaded with the core purpose and then systematically covers parameters, return values, and safety caveats. Every sentence adds information, but the length is near the upper bound for a tool definition; some of the caveat text could arguably be tightened. Still, structure is logical and skimmable.

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?

Despite having no output schema and no annotations, the description gives a complete picture: what the tool does, which network it operates on, what parameters do, what is returned, and how to interpret the results safely. The warning about trusting the agent number source and the permissionless nature of registration is critical context that would otherwise be missing. Nothing essential for correct invocation or interpretation is omitted.

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?

The input schema already covers 100% of the parameters with descriptions, so the baseline is 3. The description adds meaningful value by explaining agent_id as 'the agent's number in the Identity Registry' and by clarifying that pay_to and resource trigger comparisons against the registered wallet and on-chain domain. This goes beyond the schema's field-level 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 opens with a specific verb and resource: 'Reads an agent's ERC-8004 record from the registry on the active Base network.' It clearly distinguishes itself from sibling tools by explicitly noting it is read-only, on-chain only, and never fetches the agent's website, which separates it from x402_fetch and the balance/history 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?

The description makes the usage context clear: call it with an agent_id to read the registry record, and optionally pass pay_to/resource for comparisons. It also gives important guidance about when the result is meaningful, warning that registration is permissionless and only a mismatch is a strong signal. It does not explicitly name sibling alternatives or state 'use this instead of X', but the context is sufficiently clear.

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