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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds a useful behavioral detail: that the returned values are consistent with the public pricing URL. It does not contradict the annotations or describe return format, but that is partially covered by the output schema.

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 sentences: the first states the core function, the second provides an authoritative reference. It is front-loaded, concise, and every word earns its place with no extraneous detail.

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 has an output schema and safety annotations, so the description need not explain return values or safety. However, the input schema's pagination parameters are left completely unexplained, and the description does not mention that the tool supports pagination. This gap in parameter semantics makes the description feel incomplete for an agent that needs to invoke it correctly.

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 description coverage is 0%, so the description must compensate for parameter meaning. It fails to mention pagination parameters (page_size, starting_token) or how they affect the result. The parameter names are self-explanatory, but the description adds no context about the request object's purpose or the pagination behavior.

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: 'Check the unit consumption for each API.' It identifies a specific verb ('check') and resource ('unit consumption for each API'), and the reference URL adds specificity. This distinguishes it from sibling tools, which are mostly image/video generation tools or file upload utilities.

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 implies the tool is for retrieving API pricing information, but it does not explicitly state when to use it versus alternatives or provide any exclusions. There are no sibling tools with a similar cost-lookup role, so the usage context is inferred rather than explicit.

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