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

With no annotations provided, the description carries the full behavioral burden. It usefully discloses caching, a 24-hour TTL, no additional payment, and no new provider calls or API execution, but it omits auth requirements, error behavior for expired or invalid receipts, and idempotency details.

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 three tight sentences with no waste. It front-loads the operation and follows with availability and side-effect constraints, each sentence earning its place.

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 fetch tool with no annotations and no output schema, the description covers the main behavior and constraints. It is still incomplete because it does not explain how to obtain receipt_id or what happens when the receipt is expired, unsettled, or not owned.

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?

There is one required parameter, receipt_id, and schema description coverage is 0%. The description mentions a 'verified receipt' but does not explain what receipt_id is, where to obtain it, or how it relates to the sibling receipt tools, leaving the schema pattern as the only guidance.

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 uses a specific verb and resource: 'Fetch the original AES-GCM cached result' for a 'settled and chain-verified owned API payment.' This clearly identifies the operation and distinguishes it from general payment or receipt tools, though it does not explicitly name sibling alternatives.

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 states the prerequisite condition ('settled and chain-verified owned API payment') and the 24-hour availability window, which implies when the tool applies. However, it does not explicitly say when not to use it or route the agent to sibling tools like check_owned_receipt, locate_owned_receipt, or reconcile_gateway_receipt.

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