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

Annotations only cover readOnlyHint, and the description goes well beyond it: it discloses the tool never issues/draws/reveals a card, describes the retrievable-flag lifecycle (single-use card drawn or not), and states polling safety. This is exactly the kind of behavioral context annotations cannot carry.

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?

Front-loaded with the core purpose, then layered with operational detail; every sentence carries information about the card lifecycle or polling. Slightly long, but each clause earns its place rather than padding.

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?

With no output schema, the description compensates fully by enumerating return fields (status, denial reason, retrievable boolean, review_url) and their interpretation. Nothing an agent needs to call and interpret this tool is 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?

Schema coverage is 100% and the single request_id parameter is already documented as 'returned by request_purchase'. The description adds no syntax, format, or provenance beyond what the schema provides, so the baseline of 3 applies.

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?

States a specific verb+resource ('Check the current status of a purchase request') and immediately distinguishes itself from sibling retrieve_card by explaining the retrievable/drawn relationship. An agent can tell exactly what this tool returns and what it does not do.

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?

Explicitly instructs when to call retrieve_card ('ONCE when you are ready to pay'), when to start a new purchase, how to handle the pending_review review_url, and notes it is safe to poll. It names the sibling and the condition that selects it.

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