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

Since no annotations are provided, the description handles the behavioral disclosure. It successfully communicates that the returned data is indicative, which is essential behavioral knowledge for an agent using this tool.

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 brief and highly effective, front-loading the core function and immediately adding the necessary business context in a single, efficient sentence.

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 description is complete regarding the tool's purpose and limitations. Given the 100% schema coverage, no further information regarding inputs is strictly necessary.

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 100%, establishing the baseline of 3. The description does not add specific syntactic or semantic meaning to the parameters (like 'base' or 'assets') beyond what the schema provides.

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 identifies the tool as providing mid-market rates for specific assets against a fiat base, setting it apart from the creation and listing siblings.

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 crucial operational context by stating the rates are 'Indicative only' and contrasting this with the rate locking mechanism used when an invoice is created.

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