hetzner_get_invoice

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint as false, indicating a safe read operation. The description adds a behavioral constraint (requires environment variables) beyond the annotations, which is useful. No contradictions found.

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 consists of two short, front-loaded sentences. The first sentence states the core purpose clearly, and the second sentence adds a critical prerequisite. No verbosity or repetition; every word earns its place.

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?

Given the tool's simplicity (one parameter, read-only, output schema exists), the description adequately covers the essential information. It explains the purpose and required setup. It does not cover error handling or edge cases, but for a simple get-by-id operation, it is nearly complete.

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 input schema has one required parameter 'invoice_id' with description 'Invoice ID'. The tool description does not elaborate on the parameter's format, source, or semantics. Given that schema description coverage is 0% (the schema description is minimal and considered insufficient), the description fails to add meaningful information.

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 'Get details of a specific Hetzner Cloud invoice by ID' clearly states the verb (get details), resource (Hetzner Cloud invoice), and identifier (by ID). It distinguishes from siblings like 'hetzner_list_invoices' and 'hetzner_get_invoice_pdf', but 'hetzner_get_invoice_details' could be a direct duplicate, which slightly reduces clarity.

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 mentions prerequisites (HETZNER_ACCOUNT_EMAIL and HETZNER_ACCOUNT_PASSWORD must be set), which is helpful. However, it does not guide when to use this tool versus alternatives like 'hetzner_list_invoices' or 'hetzner_get_invoice_pdf', nor does it explain typical workflow (e.g., first list, then get).

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