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

The annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds useful behavioral context beyond that: data is live from Plesk, and the result includes quota comparison, category breakdown, and per-database size/overhead. It does not cover auth, rate limits, or error behavior, so it is strong but not exhaustive.

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 front-loaded with the core breakdown, then lists the components, then the use-case framing and alternative. It is compact and every sentence contributes to tool selection or output expectation.

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 adequately explains what the tool returns: total vs quota, category allocation, and database sizes/overhead. Combined with the rich annotations and fully documented single parameter, an agent has enough information to call this tool correctly.

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 'domain' parameter is documented with an example. The description reinforces that the breakdown is per-domain but adds no syntax, format, or constraint beyond what the schema already provides, so the baseline 3 applies.

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 operation: breaking down a domain's used storage into total vs quota, item categories (web files, databases, mailboxes, logs), and database sizes with overhead. It explicitly distinguishes itself from the sibling get_webspace_usage by naming the simpler question that sibling answers.

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 gives explicit when-to-use guidance with an example question ('Was frisst meinen Speicherplatz?') and an explicit alternative for the simpler case: for 'Wie voll ist es?' use get_webspace_usage. This is exactly the routing information an agent needs.

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