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

Adds important context beyond annotations: password is server-generated, the default home directory behavior, the warning about '/' granting full hosting access, and critically that the actual directory set must be taken from the response (not assumed). This is valuable behavioral disclosure for a mutation tool with annotations covering safety.

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?

Four sentences, front-loaded with purpose, then key default/warning, ending with a critical instruction. No significant waste, though it could be slightly tighter. Every sentence adds value.

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 mutation tool with no output schema, the description covers the main behavioral aspects: password generation, directory defaults, security implications of '/', and reliance on the response for actual directory. Missing: permissions required, whether the account is immediately active, or what the response contains beyond the directory.

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%, so the schema already fully documents parameters including validation examples for 'home'. The description adds no new parameter syntax, but does provide context on default behavior and the '/' special case. Baseline 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?

Clear verb+resource: 'Legt einen zusätzlichen FTP-Zugang für eine Domain an' (Creates an additional FTP account for a domain). The 'zusätzlich' (additional) differentiates from other creation tools, though it doesn't explicitly name the delete sibling. Purpose is specific and distinguishable.

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?

No explicit when-to-use or when-not-to-use guidance. The implicit context (creating an FTP account) is clear from the name and the note about default directory behavior hints at usage, but it lacks routing to alternatives like reset_ftp_password or delete_ftp_account.

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