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

The 'WRITE:' prefix and 'It is not sent' add meaning beyond annotations, which only declare readOnlyHint=false/openWorldHint=true and say nothing about whether the document is dispatched to the customer. It omits the non-idempotency consequence (retries may create duplicate estimates), which is the main remaining gap.

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 fragments, front-loaded with the mutation marker and the key behavioral fact ('It is not sent'). Nothing redundant.

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?

With 8 parameters, no output schema and no parameter-level return info, the description never says what comes back (presumably a new estimate id, needed for follow-up steps) or how template_id interacts with inline items. Adequate but leaves real operational gaps for a write tool.

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 88%, so the schema already documents items, currency_code, template_id and the rest. The description only gestures at 'line items' and 'customer' without adding format or defaulting rules, so it sits at the schema-covered baseline.

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 and resource ('create an estimate (quote)') plus the source of the data ('for a customer from line items'), and the parenthetical 'quote' disambiguates the term. It doesn't explicitly contrast with sibling fastbill_create_invoice, but the resource name is distinct enough to be actionable.

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 is not sent' is the only routing hint — it implies this is for a draft/proposal stage rather than billing. There is no explicit when-to-use vs fastbill_create_invoice or when to prefer template_id over inline items, so the agent must infer.

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