Account Activity Report

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

Even though annotations already declare readOnlyHint=true and destructiveHint=false, the description adds valuable behavioral context: it fetches voucher details and filters client-side, has a max_vouchers limit, and returns a summary. This goes beyond the annotations and helps the agent understand performance and output implications.

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 description is well-structured into sections: core purpose, critical warning, use cases, parameter list, return note, and examples. It is longer than average, but every section earns its place and aids correct invocation; important warnings are placed prominently.

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?

Given the absence of an output schema, the description adequately explains what the tool returns (transactions matching account criteria with optional summary). It also covers prerequisites, parameter constraints, and usage examples, making it complete for a read-only reporting tool.

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?

The input schema is empty, so the description carries the entire burden of documenting parameters. It enumerates all arguments with types, constraints (e.g., account_numbers max 20, max_vouchers 10-500, response_format enum), and concrete examples, making the tool fully invocable by the agent.

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 opens with a specific verb+resource statement: "Show all voucher transactions affecting specific account(s)." It clearly distinguishes this tool from sibling tools like fortnox_list_vouchers or fortnox_search_vouchers by focusing on account activity and account-based filtering.

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 explicitly instructs agents to call fortnox_list_financial_years first to get the correct financial year ID, and warns that the API doesn't support native account filtering, recommending date ranges to limit the scan. Common use cases with example account numbers and ranges provide actionable when-to-use guidance.

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