list_invoices

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered structurally. The description adds two things the annotations do not: the hard three-year lookback window and a security warning that invoice URLs grant access to private invoice content.

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?

Two short sentences, zero waste, with the scope limit and filter front-loaded and the privacy caveat placed after. Every clause carries information an agent can act on.

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?

An output schema exists, so return values need not be explained, and annotations cover the safety profile. The description supplies the scope, filter semantics and a privacy warning; the remaining gap is the absence of any routing hint toward get_invoice and no note on result volume/pagination for a three-year window.

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% and the single 'status' parameter is only named in the schema, not described. The description compensates by clarifying that it filters by payment status and is optional, which is the essential semantics for this lone parameter; the enum values themselves are already in the schema.

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) plus resource (invoices) and even bounds the scope to 'the past three years' with an optional filter. It does not, however, explicitly differentiate itself from the sibling get_invoice, leaving the list-vs-single distinction to inference.

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?

'Optionally by payment status' implies how to narrow results, so the usage is somewhat legible. But there is no explicit statement of when to use this instead of get_invoice, or of any prerequisites/preconditions; usage is only implied.

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