proforma_invoices_cancel

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

No annotations are provided, so the description carries some burden. It does disclose an important behavior: cancellation preserves historical record (non-destructive). However, it doesn't disclose side effects such as whether cancellation triggers notifications, whether notes/reason are mandatory, or what happens to associated records.

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?

Two concise sentences with zero waste. The first sentence states the core action, and the second adds the eligibility constraint and the key differentiator from deletion. Efficient and front-loaded.

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 cancellation tool with no output schema and no annotations, the description conveys the core purpose and constraints adequately. However, it could be more complete about what 'cancel' means in this domain — e.g., whether it affects VAT reporting, blocks further edits, or requires specific user permissions.

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 each parameter is already documented in the schema. The description adds little beyond what the schema provides. It doesn't clarify, for example, whether cancellationReason/cancellationNotes are required in practice, or whether companyId must match the proforma's company.

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 uses a specific verb+resource ('Cancel a proforma invoice') and immediately adds the key distinction from siblings: it preserves the historical record unlike deletion. This clearly distinguishes it from proforma_invoices_delete, which is the primary alternative in the sibling list.

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 states when it can be used ('from any status except converted or already cancelled'), giving clear eligibility constraints. It also implicitly differentiates from deletion by noting it preserves history, though it doesn't explicitly name the alternative tool or state when you'd prefer delete over cancel.

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