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

The annotations already establish read-only, non-destructive behavior, and the description adds substantive context: pricing at $0.01/call via x402 USDC or a card key, first 25 free, failed calls free, and that repeated calls are not free. It also reinforces that the tool reads or computes only and changes nothing, so an agent understands cost and side-effect behavior before invoking it.

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 front-loaded with purpose and usage, followed by clear cost and behavior notes. It is appropriately sized, though the charging information is slightly redundant between the explicit price and the later 'each call is charged' clause.

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 one-parameter, read-only lookup tool with annotations covering safety and no output schema, the description supplies everything needed: purpose, usage context, input range, output fields, pricing, and side-effect behavior. Nothing an agent needs in order to call it correctly appears missing.

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?

Although the single parameter is fully described in the schema, the description adds domain meaning beyond the bare 'Status code' field by specifying the valid 1xx-5xx range and calling out specific codes like 402 and 429. The example code=429 further clarifies accepted input.

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 names a specific resource and output: the name, plain-language meaning, and retry guidance for an HTTP status code. It scopes the input to 1xx-5xx and gives concrete examples, making it unmistakable versus otherwise unrelated sibling tools.

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 when handling API errors and provides an example call with code=429. There are no obvious alternative HTTP-status tools to contrast with, but it does not state any exclusions or when-not-to-use conditions.

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