expense_overview

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

The annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, openWorldHint=true, indicating a safe read operation. The description adds that the tool aggregates by currency, which is helpful but does not disclose any additional behavioral traits beyond what annotations provide. The description is consistent with annotations.

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 a single short sentence (10 words) that conveys the core functionality efficiently. It is front-loaded with the main purpose. However, it could benefit from a brief mention of output structure or aggregation details without losing conciseness.

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 tool has no output schema and is relatively simple (aggregated totals by currency), the description provides a basic understanding. However, it does not specify the output format (e.g., list of objects with currency, expense, VAT), which would help an agent interpret results. The annotations cover safety but not completeness of output.

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 has 100% description coverage for its three parameters (companyId, from, to). The description does not add meaning beyond the schema; it does not explain the aggregation logic, return format, or parameter constraints. With full schema coverage, a 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 it returns total expense and VAT amounts by currency for a date range. It uses a specific verb ('Total expense and VAT amounts') and resource ('by currency for a date range'), and it distinguishes from sibling tools like expense_monthly and finance_overview by focusing on a currency-level summary.

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 it is used for retrieving expense and VAT totals by currency, but it does not explicitly state when to use it versus alternatives (e.g., expense_monthly for monthly breakdowns or finance_overview for broader financial data). No usage guidance or exclusion criteria are provided.

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