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

Beyond the read-only and open-world annotations, it explains that validity requires Active status, an agent_uri card matching the on-chain metadata_hash, and presence of the badge on that card. It also discloses the additional CIS-8 registry check and the shared free quota of 10 calls per hour, which are material operational behaviors.

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 purpose is front-loaded, and the alternative-tool guidance and rate limit are easy to locate. However, the second sentence packs numerous return fields and validation conditions into dense prose, some of which duplicates the output schema, while 'Read-only' repeats the annotations.

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 one-parameter read operation with complete input documentation and an output schema, the description supplies the selection and invocation context an agent needs: identifier choices, precise validity semantics, the relevant sibling alternative, and quota constraints. No material prerequisite or behavioral gap is apparent.

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% and already provides the badge example, ccd:<genesis>/cis-2:<address> syntax, length limits, and registry-app Agent ID alternative. The description adds some context about where these identifiers come from, but largely restates the schema without adding validation or error-handling guidance.

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 opening sentence identifies a specific operation and resource: looking up an agent in Concordium's CIS-8004 Agent Registry using a badge, CIS-2 token address, or registry Agent ID. It also distinguishes this lookup from x402_payee_check, making its role clear among the payment-oriented siblings.

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 accepted identifier forms make the intended lookup scenarios explicit. The instruction to use x402_payee_check when checking an x402 endpoint's payTos against its seller's badge provides a concrete condition for selecting the alternative.

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