convert_manyConvert one amount into many currencies off the SAME ECB rate date, each rounded to its own minor units. For several lines at once (mixed-currency invoice lines), call it once per line: every line then shares one rate date. Unknown targets are listed, never failed.
| Name | Required | Description | Default |
|---|---|---|---|
| to | Yes | Target currencies | |
| from | Yes | ||
| amount | Yes |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description adds meaningful behavior beyond the annotations: same ECB rate date, rounding to each target's own minor units, and unknown targets being listed rather than causing failure. The annotations are all false and uninformative, so the description carries the burden well.
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?
Three dense sentences with no filler: core behavior is front-loaded, usage guidance follows, and the edge-case behavior is stated last. Every sentence 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?
Given no output schema and sparse annotations, the description covers rate-date consistency, rounding, error handling, and batch usage. It does not mention source-currency failure behavior or the response shape, but these are secondary for invoking the tool correctly.
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 coverage is only 33% because only 'to' has a description. The description partially compensates by explaining the amount, the target currencies, and rounding behavior, but it leaves 'from' semantics and amount units implicit.
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 states a specific verb ('convert'), the resource ('one amount into many currencies'), and a distinctive constraint (same ECB rate date, per-target minor-unit rounding). It also distinguishes this tool from sibling convert by emphasizing multi-currency and batch use.
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?
It gives concrete when-to-use guidance: for mixed-currency invoice lines, call once per line so all lines share one rate date. It does not explicitly name convert as the alternative, but the usage context is clear enough for an agent to route correctly.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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