Latest daily exchange rates

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the data source (Bank of Canada), frequency (daily), and quote convention (CAD per unit of foreign currency), which adds context. However, it does not disclose the response format, whether all currencies are included, or any potential limitations. This is a read-only operation by nature, but the description does not explicitly state that.

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 sentence that front-loads the core purpose and includes essential details (official, daily, CAD per unit). Every word contributes value, and there is no redundancy or wasted text.

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's simplicity (no parameters, no annotations, no output schema), the description is largely complete: it identifies the source, the type of data, and the unit convention. However, it does not specify the shape of the response (e.g., a list, a dictionary mapping currency codes to rates), which would be helpful since there is no output schema to clarify this. Still, for a simple no-parameter tool, the gap is minor.

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 tool has zero parameters, and the schema is empty. The description does not need to explain parameters since there are none. This aligns with the baseline for 0-parameter tools, and the description adds no parameter-related information because none is required.

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 'Latest official Bank of Canada daily exchange rates' with a specific quote convention (CAD per 1 unit of each foreign currency). This distinguishes it from siblings like convert_currency (which converts amounts) and search_series/get_observations (which are about series data). The verb is implicit but the resource and scope are unambiguous.

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 provides no explicit guidance on when to use this tool versus the sibling tools (search_series, get_observations, convert_currency). There is no mention of exclusions or alternatives, so the agent is left to infer usage context from the name and description alone.

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