List credit spends

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

Annotations already declare readOnly, idempotent, non-destructive, and open-world, so the safety profile is covered. The description still adds real behavior: results are ordered newest-first and paging is cursor-based by returning `next_cursor` as `cursor`. It does not say what a spend record contains or whether filters combine, but the essential call mechanics are disclosed.

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 filler, with the resource and the ordering stated up front and the pagination mechanic following. Every clause 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?

Five optional filters, no output schema, and rich annotations mean the structured data covers a lot, and the description adequately covers ordering and paging. However, it never explains what a credit spend is or how the action/product/customer filters interact, leaving an agent to infer the tool's role in the credits workflow.

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%, with every parameter documented including the `next_cursor`-to-`cursor` handoff, so the schema carries the parameter burden. The description's pagination sentence restates what the `cursor` field already says, adding no new semantics for `action`, `product`, or `customer`. Baseline 3 applies.

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 credit spends") that clearly maps to the billing/credits domain, and the resource is distinct enough from siblings like list_invoices or list_payments that an agent can tell them apart. It stops short of explicitly contrasting itself with any sibling, so a 4 rather than a 5.

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?

There is no guidance on when to use this tool versus alternatives, nor any mention of prerequisites or typical contexts (e.g., reconciling spend per customer or product). The only procedural instruction is the pagination loop, which is mechanics rather than usage guidance.

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