bnr_latest_rates

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

With no annotations provided, the description appropriately carries the burden of behavioral disclosure. It reveals the daily update time, the caching request from BNR, and the exact JSON return shape including the date and multiplier semantics. It could go further by stating what happens before 13:00, but the disclosed behavior is already substantial.

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 three sentences with no filler: it states the resource, the update/caching behavior, and the response format with an example. Every sentence earns its place, and the key purpose is front-loaded.

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 parameterless tool with no output schema, the description is complete. It explains the return object, the meaning of rate_ron and multiplier, and covers operational timing. An agent has enough context to call the tool correctly and interpret the result.

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 input schema is empty, so there is no parameter semantics burden on the description. The baseline of 4 applies, and the description even adds useful context by documenting the returned rate fields, which is more than needed.

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 opens with a specific verb and resource: 'Get today's official BNR reference exchange rates.' It clearly defines the scope (RON per foreign currency, ~37 currencies plus gold and XDR), which differentiates it from the historical sibling tools like bnr_last_10_days and bnr_year_archive.

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 phrase 'today's official' and the update cadence 'once daily after 13:00 Romania time' clearly signal when this tool is appropriate: to get the current daily rates. It also advises caching rather than polling, which is useful operational guidance. It does not explicitly name sibling tools or state when not to use them, so it stops short of 5.

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