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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds useful behavioral context beyond that: it names returned fields (id, supplierRef, date, currency, totalAmount, lines), gives the exact API path, and states the response shape as a 'paged envelope'.

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 purpose is front-loaded in the first sentence, the endpoint and return shape follow immediately, and every sentence earns its place. There is no wasted text, and the parenthetical field list is compact and useful.

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 read-only list tool with rich schema coverage and an output-less design, the description supplies what structured fields do not: the exact API route, the semantic meaning of 'bill payments', field-level return content, and the paged envelope shape. Nothing an agent needs in order to call it correctly is missing.

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 fully documents page, query, orderBy, pageSize, and companyId. The description only reinforces companyId via the endpoint path and adds no extra meaning for the pagination or filtering parameters, making the baseline 3 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?

States a specific verb ('List') and resource ('bill payments'), and immediately clarifies the resource with '(money paid out to suppliers)' and the returned fields. This distinguishes it from sibling list tools such as codat_list_payments and codat_list_bills without needing to open their schemas.

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 no explicit when-to-use guidance, no when-not-to-use conditions, and never names an alternative sibling tool. It states what the tool does but leaves the agent to infer that this is the right choice for supplier payments versus customer payments.

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