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

Beyond the annotations (readOnly, idempotent, non-destructive) it discloses sort order, the required credential and scope ('Last Price credential with billing read scope'), and a concrete failure mode: sandbox keys from self-registration get a 403 until the workspace is claimed. That is exactly the kind of operational context annotations cannot express.

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?

Three sentences, front-loaded with what is returned and in what order, then filters, then prerequisites. The list of seven returned fields is slightly long but is the only place that information exists (no output schema).

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, the description compensates by naming the returned fields; with read-only annotations, it still adds auth scope and the 403 workspace-claiming precondition. An agent has everything needed to call this successfully or diagnose a refusal.

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 limit, offset, status and customer_id are already documented with defaults and enum values. The description restates the filter semantics for customer_id and status but adds nothing on pagination behavior or amount/currency formatting, so the 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?

Specific verb+resource ('List your workspace's payments') with scope (workspace), ordering (newest first) and an enumeration of returned fields. An agent can immediately distinguish this from get_payment, which fetches a single payment.

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?

Explicitly says to pass customer_id for a single customer and status for filtering by state, giving concrete usage conditions. It stops short of naming alternatives (e.g. use get_payment for one record) or stating when not to use it, so it falls just short of the top band.

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