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

With no annotations available, the description carries the full behavioral burden and does well: it flags credential-bearing results, warns about transcript persistence, explains header precedence, and states that conflicting credentials are refused. It does not explicitly state read-only behavior or error behavior, so it is strong but not exhaustive.

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 main purpose is front-loaded, and the auth and privacy guidance is compact and relevant. The phrasing is somewhat awkward, but every sentence earns its place.

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 one-parameter lookup, the description covers the key return content, authentication, and privacy caveats. It would be more complete with an explicit output shape, id format, and a statement about read-only behavior, especially since no output schema or annotations are provided.

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 0%, so the description needs to compensate, but it only says lookup is 'by id' without defining the id format or origin. It also refers to a 'pass argument' that is not present in the input schema, which is confusing given additionalProperties is false.

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 identifies the resource and lookup scope: an invoice by id, returning its status and the pass once paid. It lacks an explicit verb like 'retrieve', and it does not explicitly differentiate itself from sibling tools, but the intended operation is reasonably clear.

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 operational guidance around authentication: prefer the Authorization header, use the pass argument only as a fallback, and never send conflicting credentials. However, it does not say when to choose this tool over claim_invoice or mint_invoice, leaving sibling selection to inference.

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