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

Since no annotations are present, the description is highly valuable. It goes beyond the technical API contract by explaining the full business flow: invoice creation -> payment option return -> payment confirmation -> credit addition.

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 three sentences are logically structured: the first defines the success/return, the second sets an operational constraint, and the third provides specific testing context, making every sentence serve a distinct purpose.

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?

Despite having no output schema, the description clearly defines what the agent should expect back (a payment option object containing an address and URL), which is necessary for successful tool usage.

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 schema coverage is only 50%, requiring the description to provide semantic value. While it confirms the nature of the payment (crypto wallet), it does not provide operational guidance on the required bundle_id or metadata construction.

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 creates a 'crypto credit purchase' and explicitly identifies the output as payment options (address/URL), distinguishing it from sibling tools like get_invoice or list_credit_bundles.

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 provides clear operational boundaries by stating what it does not handle (card/automatic top-ups, which are dashboard features) and gives specific instructions on testing ('pay it with simulate_test_payment').

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