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

The description goes well beyond the generic annotations by disclosing that the operation is irreversible, freezes the note, prevents future edits/deletions, and restricts future actions to rendering and listing. It also adds quota context ('Free tier: 10 finalized credit notes; Pro removes the limit'), which is valuable operational information an agent could not infer from the schema or annotations.

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?

Three short sentences each earn their place: the first states the core action, the second explains irreversible behavioral consequences, and the third covers quota constraints. The most important information is front-loaded, with no redundant wording or schema repetition.

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 single-parameter operation with no output schema, the description covers the essential context: what happens, what becomes impossible afterward, and the quota constraint. The only minor gap is that it does not describe what the API returns after finalization or what happens if the tool is called on an already-finalized note, but these are secondary to successful invocation.

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 id parameter is already clearly documented as 'The draft id, e.g. CN-DRAFT-2026-0001'. The description reinforces that the input is a draft, but adds no meaning beyond the schema, so the 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?

The description starts with a specific verb and resource: 'Finalize a draft', and then clarifies the exact outcome by 'burn the final CN-YYYY-NNNN number and freeze the note'. It distinguishes this from sibling tools by stating that after finalization the note 'cannot be edited or deleted, only rendered and listed', making its role and boundary clear.

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 makes it clear this tool is for converting a draft into the final client-facing document. It also implies when not to use it: after finalization, editing and deletion are no longer possible, so credit_note_update and credit_note_delete are no longer applicable. It does not explicitly name alternatives, but the usage context is sufficiently clear.

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