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

The description adds substantial behavioral context beyond the destructiveHint annotation: deletion is permanent, hours and expenses return to unbilled work, a source estimate can become an invoice again, and the draft stops counting toward the free-plan allowance. It also explains that omitting confirm yields a preview rather than performing the deletion.

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 is front-loaded with the core action and then explains consequences and the confirm requirement. Every sentence contributes useful information for a destructive operation.

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?

There is no output schema, and the description covers the key behavioral details: irreversibility, side effects on unbilled work and estimates, billing impact, and the confirm/preview distinction. An agent has enough context to invoke it correctly.

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 documents both invoiceId and confirm. The description reinforces the confirm preview behavior but does not add parameter meaning beyond what the schema already provides.

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 states a specific verb and resource: it deletes a draft invoice or estimate. It also scopes the operation to drafts only, which distinguishes it from actions on sent or numbered invoices.

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?

It clearly says the tool applies only to drafts that were not sent and have no number, and it explains that confirm: true is required. It does not explicitly name a sibling alternative such as void_invoice for non-draft invoices, so it falls short of full sibling routing guidance.

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