Resolve an ERC-8004 agent identity (read-only, on-chain)

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

With no annotations, the description carries the full burden and does it well: read-only, never writes, never touches the delivery ledger, no bundled or defaulted RPC, no canonical registry assumption, and explicit non-endorsement of registration claims. It omits error/failure behavior for an unreachable RPC or malformed compound reference, which is the one meaningful gap for a network-dependent 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?

Purpose is front-loaded in the first clause, followed by the RPC requirement and the tokenURI boundary — every main sentence carries operational weight. The closing "see DECISIONS.md D-007" pointer is internal-doc noise an agent can't act on, and "never assumed or defaulted" duplicates the rpcUrl schema text.

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?

For a 3-parameter, read-only, no-output-schema tool, the description supplies everything needed to call it correctly: prerequisites, the chain-scoped compound reference requirement, and what the return actually contains (owner plus an unresolved tokenURI pointer). Nothing material is left to inference.

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 rationale the schema doesn't: why both a registry reference and RPC are mandatory, and that no default provider or canonical address exists because ERC-8004 has independent per-chain deployments. The agentId semantics (ownerOf lookup) are also clarified as a return, not just a tokenId.

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 and resource — look up an agent's on-chain identity registration in an ERC-8004 Identity Registry — and names the exact return values (ownerOf, tokenURI). It also explicitly distances itself from the sibling delivery-ledger tools ("never touches the delivery ledger"), so an agent can route between the two families without opening a schema.

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 establishes the precondition (caller must supply BOTH a registry reference and an RPC for that chain) and the boundary condition (this tool stops at tokenURI; the caller resolves the contents). It doesn't name a sibling alternative to use for the follow-up resolution step, but the when/when-not split is otherwise unambiguous.

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