List invoices

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

Annotations already declare readOnly, non-destructive, idempotent and open-world, so the safety profile is covered. The description adds genuinely new behavior: pagination is one page per call, nextCursor must be replayed with the same store, the response shape per store (name, invoices, nextCursor null on last page), and that no match returns an empty list rather than an error.

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?

Front-loaded with purpose, then filters, then pagination mechanics, then the sibling pointer — a sensible order with no filler. The pagination sentence is somewhat run-on ("for each store its name, invoices ... and nextCursor"), costing some readability.

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?

With no output schema and eight optional parameters, the description covers what an agent needs: return shape, pagination protocol, multi-store behavior and error-free empty results. Nothing consequential is missing for correct invocation.

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 100%, so each of the eight parameters is already documented with types, bounds and enumerated values in the schema. The description adds marginal meaning beyond that — mainly the coupling of cursor with the same store and the semantics of omitting store — but does not restate filter formats or defaults.

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 and resource ("Lists invoices") plus ordering ("newest first") and the governing condition ("to find invoices when you do not have an id"). It explicitly differentiates from the sibling get_invoice, which retrieves one invoice by id.

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?

Gives an explicit selection rule against the alternative ("Use get_invoice for one invoice by id") and clarifies the multi-store case ("Without store and with several stores, one page per store"). It even documents the no-match outcome so the agent does not mistake an empty page for failure.

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