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

readOnlyHint=true already tells the agent this is a safe read, so the description only needs to add context — it contributes the chain (Base) and the fact that data comes from an on-chain registry. It says nothing about latency, caching, what happens when a DID or agentId is not found, or whether 'well-known' touches a network endpoint.

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 one-line summary, then a compact Args block; every line is short and scannable. The Args section largely duplicates the schema, which is the only noticeable redundancy.

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?

An output schema exists so return values need no explanation, and all three actions are enumerated. Still missing enough to call it complete: no routing versus the several registry siblings, no note on which action is the default entry point, and no error/absence behavior for a read that may return nothing.

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 description's Args block restates the schema text almost verbatim, including the identical example values. The one small addition is the action-to-parameter dependency, which the schema conveys less explicitly; otherwise this is baseline for fully documented 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 and resource — query the ERC-8004 on-chain agent registry on Base — and enumerates the three operations (card, resolve, well-known). The multi-mode packaging blurs the single purpose somewhat, and no sibling is named even though molcheck_registry and moltproof_registry appear adjacent.

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 Args section implies which mode to use by pairing action values with their required parameters (did for card, agent_id for resolve), which is better than nothing. But there is no explicit guidance on when to choose this registry tool over molcheck_registry or moltproof_registry, nor any stated preconditions or failure paths.

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