List invoices

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is fully covered by structured data. The description adds nothing beyond filtering surface—no mention of default page size (limit defaults to 10), result ordering, or cursor behavior, so it leaves behavioral gaps that annotation coverage only partly offsets.

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?

Very short, but the phrase "List invoices" is repeated verbatim in the title, first line, and second line, so a third of the content is pure duplication. Front-loading is fine; the redundancy is not.

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 read-only list tool with no output schema, the description is adequate but thin: it never mentions pagination via starting_after/ending_before, the created date-range object, or the default/max limit, all of which an agent must know to use it well.

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 100%, so baseline is 3; the description adds a useful gloss that the subscription filter selects invoices issued by that subscription (sbs_…). It still omits the created date-range filter and the cursor parameters, but the enum and format semantics are already carried by 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 and resource ("List invoices") in the first line, which is enough to distinguish it from siblings like get_invoice or create_invoice. It does not explicitly contrast with those siblings, but the intent is unambiguous.

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 second sentence names which filters are available (status, customer, subscription), which implies how to narrow results. However, it gives no guidance on when to use this versus get_invoice or how to page through results, so 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.