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

Annotations cover only the safety flags (readOnly=false, destructive=false, openWorld=true); the description adds substantial behavior the annotations cannot convey: the document is numbered from a number range, becomes legally binding, changes state to open, generates a PDF, and can only be undone via cancel_invoice at the cost of permanently blocking the number. It also discloses the confirmation requirement and API-key/auth dependency. No contradiction with destructiveHint=false, since finalization mutates state without deleting data.

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?

Front-loaded with the core state change, then consequences, then the alternative, then the confirmation caveat. Slightly padded by the UI reference ('Clicks Abschließen on a draft') and mild overlap between 'By default you confirm each call' and 'Reaches other people: confirm with the user before each call.'

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?

No output schema exists, and the description compensates by describing the outcome: the document gets its number, appears as open, and a PDF is generated. Combined with the irreversibility warning and the required API key, an agent has everything needed to invoke this correctly, especially compared to the surrounding lexware-office siblings.

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% for the single document_id parameter (sourced from list_documents or create_invoice), so the schema already carries the semantics. The description adds only the implicit constraint that the target must be a draft, not new parameter detail, so 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?

States a specific verb+resource (finalise a draft invoice or quote) and immediately defines the state transition: it gets its number and can no longer be edited. It also distinguishes itself from siblings by naming cancel_invoice as the reversal path and referencing list_documents/create_invoice as the source of the ID.

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?

Explicitly scopes usage to drafts of invoices or quotes and names the alternative (cancel_invoice) plus its consequence, so an agent knows what to do if reversal is needed. It also states the confirmation policy (confirm with the user before each call by default), which is actionable guidance rather than inference.

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