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

No annotations are provided, so the description carries the full burden. It mentions the return includes status and pass, but does not disclose whether it's read-only, what happens if the invoice is not paid, or any other behavioral nuances. The description indicates it returns data (status, pass), which implies a read operation, but does not explicitly state safety or side effects.

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 a single, concise sentence that is front-loaded with the main purpose. It avoids unnecessary wording and is easy to parse.

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?

Given the tool has only one parameter and no output schema, the description is fairly complete. However, it could be more explicit about the read-only nature and the exact structure of the response (e.g., what 'pass' means). But for a simple retrieval tool, it is adequate.

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?

The schema has only one parameter 'id' with 0% description coverage, so the description must compensate. It does add meaning by implying that 'id' is the identifier of the invoice to retrieve, which is helpful. However, it does not specify the format of the id (e.g., string length, pattern), but with a single parameter, this is acceptable.

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 clearly states it retrieves an invoice by id and shows its status and pass once paid. It uses specific verbs and a resource, distinguishing it from sibling tools like 'mint_invoice' (which creates) and 'claim_invoice' (which claims).

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?

It does not explicitly state when to use this tool versus alternatives. The description implies it's for fetching an invoice by ID, but there is no mention of alternatives like 'claim_invoice' or 'mint_invoice' or conditions under which to use them.

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