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

With no annotations, the description carries the full behavioral burden and does well: it explains the exact-amount matching mechanism, automatic crediting after confirmation, the returned uri, and the need to poll. It omits auth/permission expectations and failure or expiration behavior, which are material for a payment-creation tool.

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 action, followed by payment mechanics and the required follow-up in a compact sequence. No sentence is extraneous for an agent deciding whether and how to call it.

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 creation tool with no output schema, the description explains the key outcome (returned uri) and next step (poll deposit_status). It leaves some operational gaps, such as whether invoices expire, retry/idempotency behavior, and explicit auth requirements.

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 100%, so the schema already documents all three parameters including the enum and amount bounds. The description adds no parameter-specific detail beyond what the schema provides, making the baseline score 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?

States a specific verb and resource: create a crypto deposit invoice to buy credits, with supported rails enumerated. It distinguishes itself from the sibling deposit_status by instructing the agent to poll that tool for crediting status.

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?

Clear context for when to use it: buying credits via crypto without signup or card, and it names deposit_status as the follow-up tool. It does not explicitly mention create_account as a prerequisite or state exclusions, but the flow is strongly implied.

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