get_expense_summary_by_month_by_currency

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

With no annotations, the description carries the full burden, and it does disclose the return type (list of MonthCurAmtStatItem), the month format (YYYY-MM), and the date formats for parameters. It does not mention inclusivity of dates or empty-result behavior, but for a read-only summary tool this is reasonably transparent.

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 compact and front-loaded with the core purpose, followed by concise parameter and return information. No filler sentences exist; every element contributes to correct invocation.

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 simple two-parameter summary tool, the description covers the date range, required parameters, grouping, return type, and output date format. It lacks only non-essential details such as date inclusivity, ordering, or handling of empty results, so it is nearly complete.

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 0%, yet the description fully compensates by documenting both parameters with their required status, filtering role, and exact YYYY-MM-DD format. This adds meaningful semantics beyond the bare schema titles.

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 that the tool gets expense summaries aggregated by month and currency over a date range. This verb+resource+grouping is specific and distinguishes it from sibling summary tools like get_expense_summary_by_category_by_currency and get_expense_summary_by_subscription_by_currency.

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 period-based monthly/currency summaries, but it does not explicitly state when to choose this tool over the sibling summary tools. No exclusions or alternative routing are provided, so the usage context is only inferred from the name and grouping description.

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