billing_invoices_get_invoice

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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true, and destructiveHint=false, so safety and idempotency are covered by structured fields. The description adds nothing beyond that — no note on authentication, error behavior for a missing invoice, or whether the identifier is a Stripe-style ID versus a numeric key. No contradiction with annotations is present.

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 short and front-loaded with no padding, but that brevity comes from under-specification rather than precision. The duplicated name-plus-path fragment reads as generated boilerplate rather than deliberate wording.

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 simple one-parameter read tool the annotations cover the safety profile, but with 0% schema description coverage and no output schema, the description should at minimum clarify what the identifier refers to and what a successful call yields. None of that is present, so an agent has to guess at the resource semantics.

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 0% for the single required parameter, and the description only echoes "{id}" from the path template. It does not explain that the value is a billing invoice identifier or reconcile the fact that the schema types it as a number, leaving an ambiguity the schema text does not resolve.

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?

"Billing invoices get invoice" restates the tool name almost verbatim; the only added information is the HTTP path GET /billing/invoices/{id}, which implies a single-resource fetch by identifier. There is no explicit verb-plus-resource phrasing such as "Retrieve one billing invoice by ID" and no differentiation from sibling list tools like billing_transactions_get_list or companies_get_company_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?

The definition gives no when-to-use guidance, no prerequisites, and no mention of alternatives. An agent must infer from the name alone that this is the single-invoice lookup rather than a list endpoint, and nothing indicates when a not-found or unauthorized case should route elsewhere.

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