Get Income By Currency

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the description correctly aligns. It adds behavioral context beyond the annotations: the tool aggregates and does not return raw transactions, it defaults to income direction, and it includes a functional-currency total in the same set. No contradiction exists.

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: it opens with the core function, immediately follows with usage examples, then gives an exclusion, and ends with the default. Every sentence adds value; there is no redundancy or fluff.

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 read-only, idempotent tool with only three optional parameters and no output schema, the description fully covers what the agent needs: what it returns (aggregates, not transactions), the distinction between face and functional-currency totals, the direction default, and the explicit warning against using get_transactions. No critical information 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%, with each parameter (to_date, direction, from_date) already described in the input schema. The description reiterates the direction default ('Defaults to money-in') and clarifies that direction 'out' means spend, but this largely mirrors the schema. It does not add new parameter-specific semantics beyond the schema, so 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 the tool returns currency-split income or expense totals, including both face amounts per transaction currency and the functional-currency total. It uses a specific verb ('returns') and resource ('currency-split income/expense totals'), and explicitly differentiates from the sibling get_transactions by noting it returns aggregates only and not a transaction dump. This leaves no ambiguity about what the tool does.

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 gives explicit when-to-use triggers with concrete user phrasings ('total income in EUR and in GBP', 'income by currency') and a clear exclusion ('Do NOT page get_transactions to sum'). It also explains the default direction and how to switch to expense mode, providing complete routing guidance.

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