mercury_list_treasury_statements

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuinely non-obvious behavior beyond them: the PDF downloadUrl is short-lived and must be fetched shortly before download. It does not mention ordering, pagination, or how far back statements go, which keeps it from a 5.

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 purpose sentence followed by labeled USE WHEN / DO NOT USE / RETURNS blocks, each carrying distinct information. There is no filler or repetition of the schema, and the time-sensitivity caveat sits next to the use case it affects.

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 single-parameter read tool with no output schema, the definition supplies everything needed: intent, exclusions, the known failure mode (expired URL), and an inline sketch of the return shape. Nothing an agent needs in order to call it correctly is missing.

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?

Only one parameter and schema description coverage is 100% with the field documented as 'Treasury account ID', so the schema already carries the semantics. The description's phrase 'for a Mercury Treasury account' merely echoes that; no format or source-of-ID guidance is added. 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 monthly statements for a Mercury Treasury account') and immediately scopes it to Treasury, which separates it from the deposit-account and credit-card statement siblings. An agent can classify this tool from the first sentence alone.

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?

Explicit USE WHEN clause names the concrete intent (fetching a past statement URL for tax/audit export), and the DO NOT USE clause routes to the two named alternatives, `mercury_list_statements` and `mercury_list_credit_statements`. No inference is required.

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