client_statement

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

Annotations already declare readOnly/idempotent/non-destructive, so safety is covered; the description adds real behavioral detail beyond that: storno/credit documents are listed as credits and reduce the balance, and foreign-currency invoices are shown but summarised separately. It could still mention whether the statement includes paid invoices (it says unpaid only) or output format, but the added context is substantial.

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?

A single dense sentence that front-loads the resource and then enumerates the output; every clause (aging bands, credit handling, currency split) carries information, though it is close to overloaded.

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?

No output schema exists, so the description carries the burden of describing return values — and it does so thoroughly (invoice fields, totals, balance, aging-band breakdown, bank accounts). An agent knows exactly what it will get.

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 all three parameters are documented in the schema, including the asOf default of today. The description adds little beyond the schema on parameter semantics — baseline 3 is appropriate.

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/resource pair — customer statement for one client — and enumerates exactly what the output contains (unpaid invoices, totals, balance, aging bands, bank accounts). It is clearly distinguishable from the plural sibling client_statements.

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 description implies a per-client reporting use case (given a uuid and an asOf date) but never explicitly says when to prefer this over client_statements or emailing it via client_statement_email. Usage is inferable, not stated.

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