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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered; the description goes further by explaining anomalies in the returned data (missing expiry = registered elsewhere, trial subdomains never registered) and that all other tools may edit hosted domains regardless of registrar. It stops short of stating rate limits or result shape, but the added interpretive context is substantial.

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 core purpose is front-loaded in the first clause, and most sentences carry actionable meaning (registrar vs. host, trial subdomains, WordPress-vs-AI-Launch routing). It is a dense single paragraph in German with slightly overlapping clauses, so it is efficient but not maximally tight.

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 and no parameters, the description must itself explain what comes back, and it does: registrar status, expiry/auto-renew, hosting tariff, and WordPress presence per domain, plus how to interpret edge cases. An agent can call it and interpret the result correctly without further context.

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?

The tool takes zero parameters, so the schema cannot carry parameter meaning and there is nothing to describe; the baseline of 4 applies. No parameter-related confusion is possible.

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 opens with a specific verb+resource ('Den vollständigen Domainbestand des Kunden abrufen') and immediately scopes it into the two categories it covers (turbopress-registered vs. hosted-but-registered-elsewhere). It also enumerates the per-domain attributes returned (Ablaufdatum, Registrar-Status, Auto-Renew, Tarifart, WordPress-Stand), so an agent distinguishes this from get_wordpress_sites or get_dns_records without opening the 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?

It routes the agent downstream explicitly: WordPress tools only for domains with WordPress, and for AI Launch (static, no PHP) domains use the deploy_* tools. It also pre-empts a misread of the result ('a domain without expiry date is not an error'). What is missing is explicit guidance on when to call get_domains versus e.g. get_wordpress_sites or get_hosting_packages as the starting point.

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