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

The description adds useful behavioral context by disclosing the cost ($0.002 USDC via x402), which an agent would not know otherwise. However, with no annotations provided, the description carries the full burden and omits other behavioral details such as response format, idempotency, or any potential side effects, leaving gaps.

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 two short sentences, front-loaded with the primary purpose. The additional cost information is concise and relevant, with no wasted words.

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?

The tool is simple with no parameters and no output schema. The description explains what data is returned (rates) and the cost, but does not describe the response structure or data format. Given the simplicity, this is mostly complete, but it would benefit from clarifying the format or freshness of the data.

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?

There are zero parameters in the input schema, so the baseline is 4. The description does not add parameter meaning, but none is needed since the tool requires no inputs. The schema coverage is trivially 100% with no properties.

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's function with a specific verb ('Get') and resource ('Bank of Mauritius Key Repo Rate and Prime Lending Rates'). This distinguishes it from sibling tools like forex_rates or macro_indicators, making its purpose 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 guidance on when to use this tool versus alternatives. It neither states explicit prerequisites nor mentions exclusions or alternative tools. The usage context is only implied by the tool's name and description.

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