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

Annotations already indicate this is a read-only, idempotent, non-destructive, open-world operation. The description adds meaningful behavioral context beyond that: it identifies the RDAP data source, defines registry lock as serverUpdateProhibited plus serverTransferProhibited, and explains the on/partly-on/off reporting logic.

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 a single tight sentence that front-loads the data source and the core result. Every clause contributes: RDAP, the lock definition, the three-state outcome, and registrar-level locks.

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?

With no output schema, the description reasonably explains the return classification and the registrar-level lock detail. It is nearly complete for a one-parameter read-only check, though it does not mention behavior for missing domains, RDAP failures, or rate limits.

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?

There is only one parameter, and the schema already gives 100% description coverage, including that URLs are accepted and only the host is used. The tool description adds no further meaning beyond the schema, so the baseline score of 3 is appropriate.

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 states a specific verb and resource: it reads a domain's EPP status codes from RDAP and reports whether registry lock is on, partly on, or off, plus registrar-level locks. The purpose is clear, but it does not explicitly differentiate this tool from siblings such as check_seal_dns_registrar or scan_domain.

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?

There is no explicit guidance on when to use this tool versus alternatives, no stated prerequisites, and no exclusions. The use case can be inferred from the description, but the definition provides no actual usage guidance.

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