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

No annotations are provided, so the description carries the full burden of behavioral disclosure. The description implies a read-only polling operation and distinguishes the alternative flow, but does not mention idempotency, rate limits, required authentication, or what happens on success/failure. It adds some context but leaves the agent guessing on key behaviors.

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?

Two sentences with no wasted words. The primary action and key distinction are front-loaded, and the alternative guidance is provided in a single follow-up sentence. Efficient and well-structured.

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 tool with two required parameters (0% schema coverage) and no output schema, the description is under-specified. It fails to explain payment_session_id, does not describe return values or error cases, and gives no indication of polling behavior or session semantics. An agent would need significant external knowledge to call this 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. It explains that purchase_token is used for advanced generic purchases, but it does not clarify the role of payment_session_id, which is also required. This leaves a significant gap: an agent knows why to use purchase_token but not why payment_session_id is needed or how to obtain 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 states a specific action ('Poll an existing advanced generic purchase') with a clear resource (purchase) and method (using purchase_token). It also distinguishes from the standard Human Verify flow, making the purpose precise and distinct from siblings like me_status or me_receipt.

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 explicitly states when to use this tool (for advanced generic purchases) and when not to (for Standard Human Verify buyers, who should GET the status_url instead). This gives clear, actionable guidance with an alternative approach, though it doesn't name a sibling tool explicitly.

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