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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds real context beyond that — the data is fetched live from Plesk, and the scope is one domain — but it says nothing about response size, latency, or whether the numbers are cached. With annotations carrying the safety profile, a 3 is appropriate.

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?

One dense sentence enumerates the payload, then a short second sentence routes to the alternative — zero filler and the scope is front-loaded. It is a little list-heavy, but every clause maps to a real output section rather than padding.

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?

There is no output schema, so the description compensates well by naming the returned sections (quota comparison, item breakdown, database sizes with overhead). It stops short of describing ordering, pagination, or units (bytes vs MB), which an agent would still have to discover at call time.

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 a single required parameter with 100% schema description coverage ("Die Domain, z. B. example.com"), so the schema fully documents it. The description adds no format, wildcard, or ID-vs-hostname nuance beyond what the schema already states. Baseline 3 applies when the schema does the heavy lifting.

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+resource ("Aufschlüsselung des belegten Speicherplatzes einer Domain") and enumerates the exact contents: total vs quota, breakdown by web files/databases/mailboxes/logs, plus per-database size and overhead. It explicitly distinguishes itself from the sibling get_webspace_usage, so an agent can choose between them without opening either 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?

Gives an explicit decision rule and names the alternative: the diagnostic question "Was frisst meinen Speicherplatz?" is this tool, while the plain "Wie voll ist es?" is served by get_webspace_usage. Nothing is left to inference about when to prefer which.

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