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

The description adds substantial behavioral context beyond annotations: it claims the quote's status first to avoid orphan invoices, copies live line items, records converted_invoice_id, and discloses concurrency refusal behavior with recovery steps. Annotations confirm it is a non-idempotent, non-destructive mutation, and the description explains the atomic claim and error conditions thoroughly.

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 operation and structured with colons and dashes to separate concerns. It is dense but every sentence carries relevant behavioral or recovery information; slightly more conciseness could be achieved, but it avoids unnecessary 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 13-parameter mutation tool with no output schema and low schema description coverage, the description is strong on behavioral and error-handling context but weak on parameter explanations. It implies the output is a new invoice via 'NEXT: invoice_read on the new invoice,' but leaves agents without guidance on the optional invoice-override fields. Adequate for the core conversion path, but with clear gaps.

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 only 15% (13 parameters, only id and quote_id have descriptions). The description does not explain the many optional parameters (notes, status, currency, client_id, issue_date, tax_scheme, valid_until, quote_number, tax_rate_bps, prices_include_tax, converted_invoice_id). It adds some meaning for id and converted_invoice_id implicitly, but fails to compensate for the low schema coverage.

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: 'Converts a quote into its invoice in ONE call.' It also distinguishes the operation from sibling tools by naming quote_read, quote_update, quote_item, and invoice_read in context. An agent can immediately understand the tool's core function.

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 gives clear conditions for use and refusal: it refuses if the quote is already converted or declined, and it advises reviving with quote_update first. It also explains the retry path (re-read with quote_read) if the quote or lines changed. No explicit comparison to invoice_create is given, but the alternatives for error handling are well covered.

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