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

Annotations already declare readOnly, idempotent, non-destructive, and open-world behavior. The description adds useful context beyond that: it is free, requires no wallet, no payment, and no arguments, which lowers uncertainty about invocation cost and side effects.

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?

One compact sentence with the free preview purpose and invocation constraints front-loaded. Every clause earns its place and there is no repetition or filler.

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 no-argument preview tool with no output schema, the description gives sufficient context: it is free, returns a sample shape, and requires no wallet or payment. It could add whether the sample is static, but the annotations already cover idempotence and safety.

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?

With zero parameters, the baseline is 4. The description reinforces this with 'no arguments needed,' which matches the empty schema and is helpful for an agent deciding whether to call it.

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 this is a free sample response for sanctions_delta, named as OFAC sanctions list change tracking. It distinguishes itself from the paid sibling by being a preview, but it does not state a specific operation verb (e.g., 'returns a sample payload') beyond 'sample response'.

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 explicitly says to use this to see the shape before paying 0.008 USDC and notes no wallet or payment is required. The alternative (paid sanctions_delta) is named, though the description does not spell out conditions like when the paid version is necessary.

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