List billing rates

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=true, covering the safety profile. The description adds nothing beyond that: it does not mention pagination behavior, the effect of the 'full' flag on response size, default page sizes, or ordering. For a read-only list tool with annotations present, this is below the modest bar.

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 one short clause with no wasted words, so it is concise. However, it is under-specified rather than efficient, and it never states a verb or action, leaving the sentence closer to a label than a useful definition.

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?

This is a simple paginated list tool with only four parameters and a read-only annotation profile, so the burden on the description is modest. The schema documents paging and the full-output flag, and annotations cover safety, but the description supplies no return-shape, ordering, or filtering context. Adequate 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 coverage is 75%: 'full', 'page', and 'itemsInPage' are documented in the schema, while 'kind' (the required enum) has no schema description. The phrase 'products or expenses' effectively documents the two enum values, compensating for that one gap. With most parameters already covered by the schema, a baseline 3 is 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?

The fragment 'Billing rates: products or expenses.' names the resource and the two subdivisions (which map to the kind enum), so an agent can infer this lists billing rates. However, it reads as a noun-phrase restatement of the title rather than a verb+resource statement, and it omits any scope or verb. It is a weak but not tautological purpose.

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?

There is no guidance about when to use this tool versus siblings like list_invoices, list_contracts, or get_invoice, and no mention of prerequisites or alternatives. The description offers implied context only through the resource name. No when-to-use or when-not-to-use information is present.

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