Check API key and account

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

The readOnlyHint annotation already communicates that this is a safe read operation. The description adds non-obvious context about account plan quota and credit packs, and explains that 'out of pages' failures are permanent quota problems rather than transient errors. This is useful behavioral context beyond the annotations, though it does not describe the exact return payload.

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 concisely written and front-loads the core purpose before the recommended usage timing. The second paragraph about redaction billing and quota errors is somewhat tangential to what this tool itself does, but it is still relevant context and does not make the description bloated.

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?

Given the tool's simplicity, zero parameters, and no output schema, the description covers the essential what, when, and error-handling context. It does not enumerate the specific fields returned in the account status response, but the stated purpose ('see which account it belongs to') provides enough for an agent to invoke the tool correctly for its intended use.

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?

The tool has zero parameters, so there are no parameter semantics for the description to clarify. According to the baseline for zero-parameter tools, a score of 4 is appropriate.

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 states a specific verb ('check') and resource ('API key and account'), and clearly conveys the tool's diagnostic purpose. It is easily distinguishable from the sibling redaction and job-status tools because it is explicitly framed as a pre-batch validation step.

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 gives explicit when-to-use guidance: call this before a large batch to fail fast on a bad or missing key rather than after uploading. It also provides an exclusion for retrying 'out of pages' errors, which is a clear error-handling instruction that helps the agent decide when not to retry a related call.

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