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

With no annotations, the description carries the full burden and delivers: 0.005 USDC per call over x402, the alternative ARCGATE-KEY header payment path, where payment goes (params._meta['x402/payment']), the 404 unknown_chain failure mode, the empty-list-not-error behavior, and the agentId-ascending ordering. An agent knows exactly what this call costs, how to pay, and how it fails.

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?

Bold labels (Cost / Inputs / Returns / Errors / Next) make it scannable and the critical scoping facts are front-loaded. It loses a point because the pricing is stated twice — once in the Cost bullet and again verbatim in the trailing paragraph — which is pure duplication.

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?

There is no output schema, and the description compensates by describing the return shape (per-agent summary plus roles, ordered by agentId) and the empty-result case. Cost, payment, error, and next-step information are all present, so 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%, so both parameters are already documented in the schema, including the 'any letter case' detail and the unknown_chain constraint. The description mostly restates those inputs rather than adding new syntax, format, or edge-case meaning, so the baseline of 3 applies.

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 (looks up), a specific resource (the ERC-8004 agents an address owns or is the agentWallet of), and the exact relationship being resolved. It is distinguishable from the other agent-oriented siblings (agentSearch, agentProfile) because the lookup key and the ownership/agentWallet relation are named explicitly.

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 'Next' section routes the agent to agentProfile for an individual agent's checks and feedback, and the error note tells it to use only the chain this deployment serves. It gives clear context for when this is the right entry point, though it never explicitly contrasts itself with agentSearch (the other agent-listing sibling).

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