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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, but the description adds non-redundant behavioral specifics: 'return a download link valid for one hour' and 'Nothing partial is ever written.' These go beyond the annotations, offering an atomicity guarantee and output lifetime that an agent would otherwise not know.

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 sentences, front-loaded with the core action and key details, followed by a usage statement. No filler. The description is compact and 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?

No output schema exists, but the description explicitly explains the return value (a download link valid for one hour) and the file formats. It also covers the intended use case. Given the tool's simplicity and full schema coverage, nothing an agent needs 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?

Schema description coverage is 100% and the descriptions for from, to, format, path, account, and category are already clear. The description does not add meaning beyond what the schema provides – it only restates the date range and formats. With full schema coverage, the baseline of 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?

The description clearly states the action (export), the resource (bank transactions), the date range scope, and the file formats (.csv/.json). It also explicitly positions the tool as the one for 'export September' once a statement has been imported, distinguishing it from sibling tools like statement_import or transactions_list.

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?

Provides explicit context for when to use: 'once a statement has been imported.' This gives a clear precondition and implies the alternative (statement_import) without naming it. The format guidance ('csv for a spreadsheet, json for a program') further clarifies usage decisions.

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