Get a domain

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds value beyond annotations by scoping the operation to domains 'already registered in this account' and disclosing the returned data categories (status, expiry, renewal method, contacts, nameservers). No contradiction with annotations.

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?

Two sentences, zero filler, with the core purpose front-loaded in the first sentence and sibling routing efficiently packed into the second. Every clause earns its place, and the semicolon-separated alternatives remain readable.

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 single-parameter read tool with a full output schema and safety annotations, nothing essential is missing. The description covers what the tool returns, which account scope it operates on, and routes both related use cases (availability checking and search) to the correct siblings.

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 single parameter's schema description is already strong ('Fully qualified domain name, e.g. example.com, as listed by eurodns_domain_search'). The tool description adds no new parameter-level detail beyond reinforcing the account-scoping context, so the baseline of 3 is appropriate — the schema carries the burden adequately.

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 ('Returns'), a specific resource ('one domain already registered in this account'), and enumerates exactly what is returned (status, expiry, renewal method, contacts, nameservers). It also differentiates itself from sibling tools by naming eurodns_domain_check_availability and eurodns_domain_search as distinct tools for other purposes.

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 description gives explicit when-to-use guidance: 'Use it for a domain you hold'. It then names two alternatives with the conditions that select them — check availability via eurodns_domain_check_availability, find by criteria via eurodns_domain_search. This is fully explicit routing with no inference required.

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