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

Annotations are empty, so the description carries full burden. It discloses important behaviors: default max_rows=1000, default start_date=60 days, date format and GMT timezone, and a strict constraint on account_fk (int, not zero, not address). It doesn't explicitly say read-only but 'Returns' implies it, and auth is covered by required params.

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?

The opening sentences are slightly redundant ('Returns detailed account FIAT statement' and 'Returns detailed account statement...'), but the parameter documentation is thorough and well-structured. Overall it is compact and front-loaded for a 5-parameter tool.

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 an output schema present and no enums, the description covers all necessary invocation details: parameter purposes, defaults, date format, timezone, and constraints. It provides sufficient context for an agent to select and use this tool correctly without ambiguity.

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?

Despite 0% schema coverage, the description provides detailed @param explanations for all 5 parameters, including the account_fk warning (database ID, not address, not zero), max_rows default (1000), and start_date format/default/timezone. This fully compensates for the schema gap.

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?

Clearly states 'Returns detailed account FIAT statement' with a specific verb and resource, and distinctively mentions FIAT and date-range parameters. This differentiates it from sibling account_* tools.

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 usage for retrieving account statement history but does not explicitly state when to use this tool vs alternatives or provide exclusions. It gives clear functionality but lacks explicit guidance on when not to use it.

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